TWI614969B - Charge and discharge control method and lease service pricing system for grid-connected energy storing system - Google Patents

Abstract

A charging and discharging control method and a rental service pricing system for a grid-connected power storage system have a first electricity meter and a control device. The first meter measures the power demand of the power load between the grid-connected power storage system and the power load. The control device compares the power demand and setting range of the electrical load. When the power demand of the electric load is greater than the set range, the grid-connected power storage system starts to release the electric energy, and the discharge power is the difference between the electric demand and the discharge set value. When the power demand of the electric load is within the set range, the grid-connected power storage system does not release and does not store power. When the electricity demand of the electric load is less than the set range, the grid-connected storage system starts to store electric energy, and the charging power is the difference between the discharge set value and the electricity demand, and the charging and discharging power are recorded and the grid-connected type is deduced. Relevant data required for the pricing of the electricity storage system rental service.

Description

Charge and discharge control method for grid-connected power storage system and rental service pricing system

The invention relates to a charging and discharging control method and a rental service pricing system, in particular to a charging and discharging control method and a rental service pricing system for a grid-connected storage system.

The battery storage technology can be divided into a stand-alone power storage system and a grid-connected power storage system according to the application form. The independent power storage system is separated from the commercial power when used, and is applied to a separate house, a mobile device or a vehicle. The grid-connected power storage system is combined with the utility power when it is used. Some of the power sources are commercial power, and some are battery storage. They are usually used in non-mobile facilities such as homes, shops, offices, factories, etc.

Independent power storage systems are most commonly used in electric vehicles, but battery cost, depreciation, management and longevity issues have caused consumers to stay behind. The industry has developed a battery rental service system to reduce the cost of car purchases, eliminate the risk of depreciation and provide batteries. Regulatory services. The pricing method of the independent power storage system is to calculate the price according to the degree of charge, that is, the price is calculated according to the amount of electricity entering the battery during charging. In addition, there is also a monthly rental fee method. For example, the user estimates the number of kilometers traveled per month, and selects the driving level to pay the monthly fee.

The grid-connected power storage system is connected in parallel with the mains, and its operation mode is closely related to the charging method of the power company. The power company's charges are divided into two items. One is the amount of mobile electricity used for a period of time. The current electricity price varies according to the demand during the period. The peak electricity price is the highest, the half peak power price is the second, and the peak electricity price is the lowest. The other is the basic electricity fee, which is based on the contract capacity signed between the electricity user and the power company. The basic electricity fee is proportional to the contract capacity. If the maximum demand for power use exceeds the contracted capacity during a period of time, an additional penalty of an additional penalty will be required. Taiwan Power Company defines a period of time that refers to a month, the average power of 15 minutes, different countries or power companies have different definitions.

If the grid-connected power storage system is applied to the hot pot restaurant using the induction cooker, the peak demand for starting the meal in the hot pot restaurant can be reduced; the laundry that uses the electric drying laundry can reduce the power spike of the post-washing drying process; It can be used in residential buildings to reduce the electricity demand for air conditioning in summer and night.

In addition, the existing grid-connected power storage system architecture does not apply to rental pricing. The measurement position of the load demand for electric power in the conventional grid-connected power storage system is located at the front end of the power storage device, as shown in the position of the utility electric meter in FIG. When the load demand is constant, the storage system starts to discharge, and the demand value measured by the city electricity meter will decrease, but the original load condition cannot be presented, as shown in Figure 2. Since the electricity meter of the conventional grid-connected power storage system cannot propose the objective contribution of the power storage system, such as how much electricity is charged, how much electricity is charged, and how much is required, and thus the request for payment cannot be made to the user, the existing architecture is not suitable for Lease pricing. In addition, it can also handle the charging and discharging control problem of the grid-connected storage system.

The invention provides a charge and discharge control method and a rental service pricing system for a grid-connected power storage system, which can control the power storage system in a concise and accurate manner, and provide a calculation of the charge and discharge amount and the reduction demand of the grid-connected power storage system. The method fully presents the operational results, and then proposes a new storage system rental service pricing system.

The charge and discharge control method of the grid-connected power storage system disclosed in the present invention includes measuring the power demand of the power load. The measurement location is between the grid-connected storage system and the electrical load. Compare the power demand and setting range of the power load. The setting range includes a discharge set value and a charge set value, and the discharge set value is a set value of the grid-type storage system starting to discharge, and the charge set value is a set value of the grid-connected power storage system starting to be charged, and is less than or equal to the discharge set value. . When the electricity demand of the electric load is greater than the set range, the grid-connected storage system starts to release the electric energy, and the discharge power of the grid-type storage system is the difference between the electric demand and the discharge set value. When the power demand of the electric load is within the set range, the grid-connected power storage system does not release and does not store power. When the electricity demand of the electric load is less than the set range, the grid-connected storage system starts to store the electric energy, and the charging power of the grid-type storage system is the difference between the discharge set value and the electricity demand.

The rental service pricing system of the grid-connected power storage system disclosed by the invention has a first electricity meter and a control device. The first meter measures the power demand of the power load, and the measurement position is between the grid-connected power storage system and the power load. The control device is electrically connected to the first electricity meter and the grid-connected power storage system, and compares the power demand and the set range of the power load. The setting range includes the discharge set value and the charge set value, and the discharge set value is a set value at which the grid-connected storage system starts to discharge. The charging setting value is a set value of the grid-connected power storage system starting to be charged, and is less than or equal to the discharge setting value. When the power demand of the electric load is greater than the set range, the control device controls the grid-connected power storage system to start discharging the power, and the discharge power of the grid-connected power storage system is the difference between the power demand and the discharge set value. . When the power demand of the electric load is within the set range, the control device controls the grid-connected power storage system not to release and does not store the power. When the power demand of the electric load is less than the set range, the control device controls the grid-connected storage system to start storing the power, and controls the charging power of the grid-connected storage system to be the difference between the set value of the discharge and the demand for electricity. .

According to the charge and discharge control method and the lease service pricing system of the grid-connected power storage system disclosed in the above invention, the grid-connected power storage system can store power during a period when the power demand of the power load is small, so as to be used The electrical load releases the stored electricity during periods of high electricity demand, thereby reducing the mobile electricity bill and reducing the maximum demand during the pricing period to reduce the basic electricity bill or fine. Furthermore, since the grid-connected power storage system has the problems of high battery cost, depreciation, management, and longevity, the grid-connected power storage system is difficult to push. Therefore, the embodiment of the present invention further configures the first meter to be connected to the grid type. Between the electrical system and the electrical load, the power usage of the electrical load is fully presented, and it is avoided that the utility model can only be used when the grid-connected power storage system is connected to the utility power system and is supplied to the power load. The problem of power usage of the electrical load. In the embodiment of the present invention, by presenting the actual power usage status of the power load, the development of the grid-connected power storage system rental system makes the cost of the grid-connected power storage system more acceptable to everyone, thereby improving the degree of use.

The above description of the disclosure and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention, and to provide further explanation of the scope of the invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a schematic diagram showing the arrangement of a grid-connected power storage system in a conventional technology. The grid-type power storage system is powered by the utility power supply to the power load, and the grid-type power storage system is set. Between the load and the utility meter, FIG. 2 is a power curve diagram of the discharge power of the grid-connected power storage system and the measurement of the utility meter in the prior art. When the electric load is fixed and the grid-connected storage system is discharged, the power from the mains entering the system is reduced, and the power measured by the mains meter is degraded, and the actual power consumption of the electric load cannot be presented, as shown in FIG. .

Therefore, the embodiment provides a rental service pricing system, which can be used to control the charging and discharging of the grid-connected power storage system, and record the actual power consumption status of the power storage load, and evaluate the contribution of the actual power supply of the grid-connected power storage system, thereby calculating the lease. The price of the grid-connected storage system.

Please refer to FIG. 3. FIG. 3 is a functional block diagram of a grid-connected power storage system according to an embodiment of the invention. As shown in FIG. 3, the grid-connected power storage system 1 has a grid-connected control module 10, a communication module 12, a frequency converter 14, a battery protection module 16, a battery management module 18, and a battery module 19. In use, the grid-connected control module 10 detects the mains voltage, frequency and phase, and controls the inverter 14 to convert the DC power in the battery module 19 into an AC power of the same frequency and phase as the mains, and then in parallel with the mains. The grid control module 10 also receives the control signal through the communication module 12, and adjusts the discharge power or the charging power of the inverter 14 according to the control signal. The communication module can be RS232, RS485, CANBUS or other suitable communication interface. The control signal is, for example, an analog signal or a digital signal, for indicating the content of signals such as 0~10V and 4~20mA. The battery protection module 16 is used to ensure that the battery module 19 is not overcharged, over-discharged, over-current, over-heated, and short-circuited to isolate the external circuit and the battery module 19. The battery management module 18 is configured to detect the charging and discharging state of the battery module 19, and timely control the battery protection module 16 to manage the charging and discharging of the battery module 19, so that the battery module 19 has a considerable amount, and He Batteries with different performances can be effectively managed to avoid over-discharge.

Referring to FIG. 3 to FIG. 5, FIG. 4 is a functional block diagram of a rental service pricing system according to an embodiment of the invention, and FIG. 5 is a grid-connected power storage according to an embodiment of the invention. Power curve of system, mains system and first meter measurement. As shown in FIG. 4, in the present embodiment, the rental service pricing system 2 has a first electric meter 20 and a control device 22. The first electric meter 20 is set at the load demand measuring point, and the load demand measuring point is located between the grid-connected power storage system 1 and the electric load 3, and the first electric meter 20 is used to measure the electric power of the electric load 3 Demand, in order to fully present the original power load 3 power usage status, rather than measuring the grid-connected power storage system 1 and the mains system 4 combined to supply power to the power load 3, the mains system 4 power supply to the power load 3 Power supply status.

As shown in FIG. 4, the control device 22 is connected to the first electric meter 20, so that the control device 22 reads the electric power demand of the electric load 3 by using the first electric meter 20 to control the grid-connected electric storage system 1, for example, the control device 22. The control signal is outputted, and the control signal is received by the communication module 12 of the grid-type power storage system 1 so that the grid-connected control module 10 adjusts the discharge power or the charging power of the inverter 14 according to the control signal, but is not limited thereto. In detail, the control device 22 compares the power demand of the electrical load 3 with a set range. The setting range includes a discharge set value and a charge set value, and the discharge set value is a set value at which the grid-connected power storage system 1 starts to discharge, and the charge set value is a set value at which the grid-connected power storage system 1 starts charging. The charge set value is less than or equal to the discharge set value. When the power demand of the electrical load 3 is higher than the set range, that is, greater than the discharge set value, the control device 22 controls the grid-connected power storage system 1 to start discharging the power, and controls the grid-connected power storage system 1 to discharge the power. The discharge power is the difference between the power demand and the discharge set point. When the power demand of the electric load is within the set range, that is, between the discharge set value and the charge set value, the control device 22 controls the grid-type power storage system 1 not to release and does not store the power. When the power demand of the electrical load 3 is less than the set range, that is, less than the charging set value, the control device 22 controls the grid-connected power storage system 1 to start storing the power, and controls the grid-connected power storage system 1 to store the power. The charging power is the difference between the discharge set value and the power demand.

The discharge setting value is determined according to factors such as the demand to be suppressed, the maximum output power of the grid-connected storage system 1 and the power storage capacity of the grid-connected storage system 1. The charging setting value is to avoid the grid-connected power storage system 1 from oscillating between charging and discharging, which is usually smaller than the discharge setting value, and the offset is related to the characteristics of the grid-connected power storage system 1.

The power demand of the electrical load 3 is the average power value of the time interval, and may also be the moving average power value of the time interval. The length of a period of time can be adjusted in line with the power company's demand definition or special needs. For example, Taiwan Power Company defines the average power demanded by 15 minutes, and the electricity demand measured by the first electricity meter 20 is the average power of the electric load 3 every 15 minutes. Since different countries or power companies have different definitions of electricity demand, the electricity demand measured by the first electricity meter 20 can be adjusted according to the demand definition or special demand of each power company.

In one embodiment, the control device 22 records the first meter in one pricing period, in addition to charging and discharging the grid-type power storage system 1 according to the power demand of the electrical load 3, as described in the foregoing embodiment. 20 The read power demand, the discharge power and the charging power of the grid-connected power storage system 1 are used to generate the storage system operation statistics during the pricing period. The statistics of the operation of the power storage system include the maximum reduction demand during the period, the degree of charge during the period, and the degree of discharge during the period.

Referring to FIG. 3 to FIG. 8 , FIG. 6 is a functional block diagram of a control device according to an embodiment of the invention. FIG. 7 is a control logic diagram of a control device according to an embodiment of the invention. FIG. 8 is a schematic diagram showing power demand, charging power, and discharging power according to an embodiment of the invention. As shown, the control device 22 has a communication interface 221, a processing unit 222, and a storage unit 223. The communication interface 221 is electrically connected to the first electricity meter 20 and the grid-connected power storage system 1. In step S501, the processing unit 222 reads the power consumption of the first electric meter 20 for measuring the electric load 3 through the communication interface 221 . In step S503, the processing unit 222 calculates the average value of the power consumption of the electrical load 3 for a period of time according to the read power consumption, and obtains the power demand of the electrical load 3, and in step S505, the processing unit 222 stores The power consumption of the electrical load 3 is required by the storage unit 223. In step S507, the processing unit 222 determines whether the power demand of the electrical load 3 is greater than the discharge set value. In step S509, when the power demand of the electrical load 3 is greater than the discharge set value, the processing unit 222 outputs a control signal to the grid-connected power storage system 1 through the communication interface 221, and controls the grid-connected power storage system 1 to discharge. The power begins to discharge. The discharge power is the difference between the power demand and the discharge set value, and in step S511, the value of the discharge power is stored.

In step S513, when the power demand of the electrical load 3 is not greater than the discharge set value, the processing unit 222 determines whether the power demand of the power load 3 is less than the charge set value. In step S515, when the power demand of the electrical load 3 is less than the charging set value, the processing unit 222 outputs a control signal to the grid-connected power storage system 1 through the communication interface 221, and controls the grid-type power storage system 1 to charge. The power starts to charge. The charging power is the difference between the discharge set value and the power demand, and in step S517, the processing unit 222 stores the value of the charging power in the storage unit 223. When the power demand of the electrical load 3 is not greater than the discharge set value and not less than the charge set value, that is, between the discharge set value and the charge set value, the processing unit 222 outputs the control signal to the communication interface 221 to The mesh type power storage system 1 controls the grid-connected power storage system 1 to be uncharged or discharged.

In one embodiment, in the statistics of the operation of the power storage system during the pricing period, the maximum demand during the period is the maximum power demand of the power load 3 minus the maximum demand of the utility meter, that is, The maximum value of the electricity demand in the city during the pricing period. In other words, the pricing period is, for example, the charging period of the power company, for example, the electricity fee is calculated once per month, and the pricing period is one month, but not limited thereto. The charging degree during the period is the sum of the charging power of the grid-connected storage system 1 and the number of charging power storage per hour. The period of discharge is the discharge power of the grid-type storage system 1 during the pricing period divided by the hourly rate. The sum of the number of times the discharge power is stored.

In another embodiment, in the statistics of the operation of the power storage system during the pricing period, the maximum reduction demand during the period is the highest power demand of the electricity load 3 minus the maximum demand of the electricity electricity bill during the pricing period. The maximum demand for the city electricity bill in the same period is the highest demand for the electricity bill in the middle of the same period. In other words, during the pricing period, for example, during the charging period of the power company, the highest demand for the electricity and electricity bills is the highest demand for the power company, but not limited to this.

In the data presented by the statistical data of the operation of the power storage system, the charging degree of the period is divided by the degree of charging during the period, and the charging efficiency of the grid-connected power storage system 1 can be obtained. The charging efficiency is an important basis for judging the advantages and disadvantages of the power storage system. During the period, the maximum reduction in demand, the number of discharges during the period and the degree of charge during the period can be used as the basis for the calculation of the effectiveness and lease of the grid-connected storage system.

In the foregoing embodiment, since the control device controls the charging power and the discharging power of the grid-connected power storage system 1 as the command value, the charging power and the discharging power recorded by the control device may have a time drop and a command value during actual operation. The difference or other possible cause causes the period of the record to be reduced, the period of discharge, and the period of charge to be different from the actual value.

Therefore, please refer to FIG. 9. FIG. 9 is a functional block diagram of a grid-connected power storage system according to another embodiment of the present invention. As shown, the rental service pricing system 6 has a first electric meter 60 and a control device. 62 and second meter 64. The first electric meter 60 is disposed on the load demand measuring point, and measures the electric power demand of the electric load 3. The second electricity meter 64 is electrically connected between the grid-connected power storage system 1 and the power line, between the power line electrical connection power load 3 and the mains system 4, and also in the first meter of the rental service pricing system 6 and the mains system 4 In order to directly measure the charging power and the discharging power of the grid-connected power storage system 1, the control device 62 is more accurate according to the storage system operating statistics recorded by the second meter 64.

The second electric meter 64 has a function of integrating the output electric power and the input integrated electric power, and the output integrated electric power of one period of the counting period is equivalent to the period discharging degree, and the input integrated electric power of one period of the counting period is equivalent to the period charging degree.

Referring to FIG. 9 to FIG. 11 , FIG. 10 is a functional block diagram of a control device according to another embodiment of the present invention, and FIG. 11 is a control device according to another embodiment of the present invention. Logic diagram. As shown, the control device 62 has a communication interface 621, a processing unit 622, and a storage unit 623. The communication interface 621 is electrically connected to the first electricity meter 60, the second electricity meter 64, and the grid-connected power storage system 1. In step S701, the processing unit 622 reads the power consumption of the first electrical meter 60 for measuring the electrical load 3 through the communication interface 621. In step S703, the processing unit 622 calculates the average value of the electric power used by the electric load 3 for a period of time according to the read electric power, and obtains the electric power demand of the electric load 3, and in step S705, the processing unit 622 stores The power consumption of the electrical load 3 is required to be stored in the storage unit 623. In step S707, the processing unit 622 determines whether the power demand of the power load 3 is greater than the discharge set value. In step S709, when the power demand of the electrical load 3 is greater than the discharge set value, the processing unit 622 outputs a control signal to the grid-connected power storage system 1 through the communication interface 621, and controls the grid-type power storage system 1 to discharge. The power begins to discharge. The discharge power is the difference between the power demand and the discharge set point. In step S711, the processing unit 622 reads the second electric meter 64 through the communication interface 621 to measure the discharge power of the grid-type power storage system 1, and stores the value of the discharge power in step S713.

In step S715, when the power demand of the electrical load 3 is not greater than the discharge set value, the processing unit 622 determines whether the power demand of the power load 3 is less than the charge set value. In step S717, when the power demand of the electrical load 3 is less than the charging set value, the processing unit 622 outputs a control signal to the grid-connected power storage system 1 through the communication interface 621, and controls the grid-type power storage system 1 to be charged. The power starts to charge. The charging power is the difference between the discharge set value and the power demand. In step S719, the processing unit 622 reads the second electric meter 64 through the communication interface 621 to measure the charging power of the grid-type power storage system 1. In step S7217, the processing unit 622 stores the value of the charging power in the storage unit 623. When the power demand of the electrical load 3 is not greater than the discharge set value and not less than the charge set value, that is, between the discharge set value and the charge set value, the processing unit 622 outputs the control signal to the communication interface 621 to The mesh type power storage system 1 controls the grid-connected power storage system 1 to be uncharged or discharged.

In practice, the grid-connected power storage system 1 has a frequency converter and a battery module. The output power of the battery module should be greater than or equal to the output power of the inverter, and the output power of each battery in the battery module is limited. Therefore, the inverter with a certain output power must be matched with a certain number of batteries for the system to work normally. For applications where the output power requirements are the same and the usage is high, more batteries must be added. If the grid-connected power storage system 1 is only charged according to the maximum output power of the inverter and the maximum battery capacity, it is unfair to the number of uses, and the battery cost for different users during the same period is the same. Different charging standards must be set for different users, which will complicate the charging standard.

In order to make the charging standard reasonable and simplified, the grid-type storage system 1 charging standard can be divided into three aspects. The first type is designed according to the equipment supplier's point of view. That is to say, the rental service pricing system is based on the size of the rented inverter and the number of batteries. The inverter has a higher capacity and a higher charge. . For example, the inverter rent is $300/kW, and the battery rent is $20/kWh. If the inverter is 50kW and the battery is 1,000kWh, the monthly charge is 50kW*$300/kW + 1,000 kWh *$20/kWh = $35,000.

The second is to design the charging standard according to the user's true benefit. The charging standard will be divided into two categories, one is the demand reduction fee, the maximum reduction demand (kW) is calculated during the period, and the other is the battery. The usage fee is calculated based on the degree of discharge (kWh). During the period, when the demand is reduced, the demand is reduced, and the battery usage fee is high. The rental service pricing system calculates the method of leasing the price of the grid-connected storage system. For example, the maximum demand for period reduction is $300/kW, and the equipment usage fee is $20/kWh. When the maximum reduction during the pricing period is 50kW and the battery is discharged at 1,000kWh, the monthly charge is 50kW*$300/kW + 1,000 kWh *$20/kWh = $35,000.

The third type is designed according to the benefit of the equipment supplier and the user. The charging standard will be divided into two categories, one for equipment usage and the other for battery usage. The rental service pricing system calculates the rental price of the grid-connected storage system 1 based on the capacity of the inverter and the number of discharges during the period.

In summary, the embodiments of the present invention provide a charging and discharging control method and a rental service pricing system for a grid-connected power storage system. By setting the first electric meter to measure the point of the electric load demand between the grid-connected storage system and the electric load, thereby fully presenting the power usage status of the electric load, and solving the conventional utility electric meter is added and After the grid-type storage system is powered by the utility system and supplied to the power load, the actual power usage of the power load cannot be presented. The rental service pricing system further records the maximum reduction demand, period charge and period discharge during the period, which is used as the basis for reducing the demand for the grid-connected storage system, and is further used to calculate the lease of the grid-connected storage system. price.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

1‧‧‧Grid-type power storage system

10‧‧‧Grid Control Module

12‧‧‧Communication Module

14‧‧‧Inverter

16‧‧‧Battery protection module

18‧‧‧Battery Management Module

19‧‧‧ battery module

2. 6‧‧‧ Rental service pricing system

20, 60‧‧‧ first electric meter

22, 62‧‧‧ control device

221, 621‧‧‧ communication interface

222, 622‧‧ ‧ processing unit

223, 623‧‧‧ storage unit

3‧‧‧Electric load

4‧‧‧Power system

64‧‧‧Second electricity meter

1 is a schematic view showing the arrangement of a grid-connected power storage system in the prior art. 2 is a power curve diagram of a discharge power of a grid-connected power storage system and a city electric meter measured in the prior art. FIG. 3 is a functional block diagram of a grid-connected power storage system according to an embodiment of the invention. 4 is a functional block diagram of a rental service pricing system according to an embodiment of the invention. FIG. 5 is a power graph of the electrical load power, the utility meter measurement result, and the first meter measurement result according to an embodiment of the invention. FIG. 6 is a functional block diagram of a control device according to an embodiment of the invention. FIG. 7 is a control logic diagram of a control device according to an embodiment of the invention. FIG. 8 is a schematic diagram showing power demand, charging power, and discharging power according to an embodiment of the invention. FIG. 9 is a functional block diagram of a rental service pricing system according to another embodiment of the present invention. FIG. 10 is a functional block diagram of a control device according to another embodiment of the present invention. 11 is a control logic diagram of a control device according to another embodiment of the present invention.

1‧‧‧Grid-type power storage system

2‧‧‧Rental service pricing system

20‧‧‧First electricity meter

22‧‧‧Control device

3‧‧‧Electric load

4‧‧‧Power system

Claims (22)

A charging and discharging control method for a grid-connected power storage system includes: measuring a power demand of a power load, and measuring a position between a grid-connected power storage system and the power load; comparing the use The power demand of the electric load and a set range, the set range includes a discharge set value and a charge set value, and the discharge set value is a set value of the grid-connected storage system starting to discharge, the charge set value is The set value of the grid-connected power storage system starts to be charged, and is less than or equal to the discharge set value; when the power demand of the power load is greater than the set range, the grid-connected power storage system starts to discharge power. A discharge power of the grid-connected power storage system is a difference between the power demand and the discharge set value; and when the power demand of the power load is within the set range, the grid-connected power storage system The battery is not discharged and does not store power; and when the power demand of the power load is less than the set range, the grid-connected power storage system starts to store power, and a charging power of the grid-connected power storage system is the discharge The difference between the set value and the demand for electricity . The charging and discharging control method of the grid-connected power storage system according to claim 1, wherein the power demand of the power load is an average power value of a time interval or a moving average power value of the time interval. The charging and discharging control method of the grid-connected power storage system according to claim 1, further comprising recording the power demand of the power load during a charging period, and the discharging power of the grid-connected power storage system The charging power is generated to generate a storage system operation statistic during the charging period. The charging and discharging control method of the grid-connected power storage system according to claim 3, wherein the storage system operation statistics during the charging period includes a maximum reduction requirement during a period, and the maximum reduction requirement during the period is the meter The maximum electricity demand of the electricity load during the fee period is subtracted from the maximum demand of the city electricity meter. The charging and discharging control method of the grid-connected power storage system according to claim 3, wherein the storage system operation statistics during the charging period includes a maximum reduction requirement during a period, and the maximum reduction requirement during the period is the meter The highest demand for the electricity load in the fee period minus the maximum demand for the electricity bill of the city. The charging and discharging control method of the grid-connected power storage system according to claim 5, wherein in the charging system operating statistics during the charging period, the discharging power in the charging period is divided by the number of discharging power per hour. The sum is the number of discharge degrees during a period, and the sum of the charging power divided by the number of charging power storages per hour during the charging period is the number of charging periods. The charging and discharging control method of the grid-connected power storage system according to claim 6, further comprising calculating the grid-connected type by the maximum reduction demand during the period, the degree of discharge during the period, the degree of charge during the period, the capacity of the inverter, and the battery capacity. The rental price of the electricity storage system. The charging and discharging control method of the grid-connected power storage system according to claim 6, further comprising calculating the rental price of the grid-connected power storage system by using the inverter capacity and the battery capacity. The charging and discharging control method of the grid-connected power storage system according to claim 6, further comprising calculating the rental price of the grid-connected power storage system by the maximum reduction demand during the period and the degree of discharge during the period. The charging and discharging control method of the grid-connected power storage system according to claim 6, further comprising calculating the rental price of the grid-connected power storage system by the capacity of the frequency converter and the degree of discharge during the period. The charging and discharging control method of the grid-connected power storage system according to claim 6, further comprising measuring the charging power, the discharging power, the discharging degree during the period, and the charging period of the grid-connected power storage system by using an electric meter. The power meter is electrically connected between the grid-connected power storage system and a power line, and the power line is electrically connected between the power load and a utility system. A rental service pricing system for a grid-connected power storage system includes: a first electricity meter that measures a power demand of a power load, and the measurement location is a grid-connected power storage system and the power load And a control device electrically connecting the first electricity meter and the grid-connected power storage system, comparing the power demand of the power load with a setting range, the setting range includes a discharge setting value and a charging a set value, the discharge set value is a set value of the grid-connected storage system starting to discharge, the charge set value is a set value of the grid-connected power storage system starting to be charged, and is less than or equal to the discharge set value, when the When the power demand of the electric load is greater than the set range, the control device controls the grid-connected power storage system to start releasing power, and controls a discharge power of the grid-connected power storage system as the power demand and a difference between the discharge set values, when the power demand of the power load is within the set range, the control device controls the grid-connected power storage system not to release and does not store power, when the power load is Electricity demand is less than this setting A range, the control means controls the power storage system and the grid start storing electrical energy, and controlling the grid-connected power storage system for a charging power setting value of the difference between the discharge amount of the electricity demand. The lease service pricing system of the grid-connected power storage system of claim 12, wherein the power demand of the power load is an average power value of a time interval or a moving average power value of the time interval. The rental service pricing system of the grid-connected power storage system of claim 12, wherein the control device further records the power demand of the power load during a billing period, and the grid-connected power storage system The discharge power and the charging power are used to generate a storage system operation statistic during the charging period. The rental service pricing system of the grid-connected power storage system according to claim 14, wherein the storage system operation statistics of the charging period include a maximum reduction requirement during a period, and the maximum reduction demand during the period is the meter The maximum electricity demand for the electricity load during the fee period is subtracted from the maximum demand for the electricity meter of the city. The rental service pricing system of the grid-connected power storage system according to claim 14, wherein the storage system operation statistics of the charging period include a maximum reduction requirement during a period, and the maximum reduction demand during the period is the meter The highest demand for the electricity load in the fee period minus the maximum demand for the electricity bill of the city. The rental service pricing system of the grid-connected power storage system according to claim 16, wherein in the charging system operation statistics during the charging period, the discharging power in the charging period is divided by the number of discharging power per hour. The sum is the number of discharge degrees during a period, and the sum of the charging power divided by the number of charging power storages per hour during the charging period is the number of charging periods. The rental service pricing system of the grid-connected power storage system according to claim 17, wherein the control device calculates the maximum reduction demand during the period, the degree of discharge during the period, the degree of charge during the period, the capacity of the inverter, and the battery capacity. The rental price of the grid storage system. The lease service pricing system of the grid-connected power storage system according to claim 17, wherein the control device calculates the lease price of the grid-connected power storage system lease by using the inverter capacity and the battery capacity. The rental service pricing system of the grid-connected power storage system according to claim 17, wherein the control device calculates the rental price of the grid-connected power storage system by the maximum reduction demand during the period and the discharge degree during the period. The rental service pricing system of the grid-connected power storage system according to claim 17, wherein the control device calculates the rental price of the grid-connected power storage system by the capacity of the frequency converter and the degree of discharge during the period. The rental service pricing system of the grid-connected power storage system of claim 17, further comprising a second electricity meter electrically connected between the grid-connected power storage system and a power line, and the power line The electric meter is electrically connected to a mains system, and the second electric meter measures the charging power, the discharging power, the discharging degree of the period, and the charging degree of the grid-connected electric storage system.