Energy storage system, control method and device thereof and storage medium

Abstract

The invention relates to the field of energy storage systems, in particular to an energy storage system, a control method and device thereof and a storage medium. The method comprises the following steps: determining an energy storage source ratio in a divided calculation period according to the divided calculation period; determining the energy storage cost in the energy storage system according to the energy storage source proportion; and performing optimization control on the energy storage system according to the energy storage cost. As the energy storage cost is determined according to the energy storage source proportion determined by the charging and discharging operation, a more accurate energy storage cost calculation result can be obtained by effectively combining the historical charging and discharging operation, thereby being beneficial to reliably reducing the cost of the energy storage system and improving the benefit of the energy storage system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage systems, and particularly relates to an energy storage system, a control method and device thereof, and a storage medium. BACKGROUND

[0002] The energy storage system includes a photovoltaic energy storage combined power supply system and a wind power energy storage combined power supply system. The energy storage system can store the electric energy generated by the power generation equipment, such as photovoltaic power generation equipment or wind power generation equipment, and release it at an appropriate time. In the context of energy shortage, the photovoltaic energy storage system has been widely used. The energy storage system relying on the power generation equipment such as light energy and wind energy can effectively alleviate the intermittency and instability of photovoltaic power generation or wind power generation, and through the peak clipping and valley filling control mode, the electricity cost of access to the power grid can be effectively reduced.

[0003] However, the power generation characteristics of the new energy power generation system such as photovoltaic power generation and wind power generation have strong timeliness, and the electricity price in most areas also has time sequence characteristics. Based on the traditional "two charging and two discharging", that is, charging in the period of low electricity price and more power generation, and discharging in the period of high electricity price and less power generation, the control mode is not conducive to effectively reducing the electricity cost and obtaining more benefits for the energy storage system. SUMMARY

[0004] Therefore, the embodiments of the present application provide an energy storage system, a control method and device thereof, and a storage medium, to solve the problem that the control method in the prior art is not conducive to effectively reducing the electricity cost and obtaining more benefits.

[0005] A first aspect of the embodiments of the present application provides a control method of an energy storage system, the method comprising: determining an energy storage source proportion in a divided calculation period according to the divided calculation period; determining an energy storage cost in the energy storage system according to the energy storage source proportion; and performing optimization control on the energy storage system according to the energy storage cost.

[0006] The embodiment of the application divides the calculation period, predicts the proportion of the energy storage source of the energy storage system in the divided calculation period, which can include the proportion of the energy provided by the power grid and the proportion of the energy provided by the power generation device. The power generation device can include a photovoltaic power generation device, a wind power device, etc. Based on the determined proportion of the energy storage source, the influence of the energy storage change in the calculation period on the energy storage cost in the energy storage system can be determined. For example, in the calculation period, the energy storage source is all the power output by the power generation device, and then the energy storage cost at the end of the calculation period can be obtained according to the power generation cost of the power generation device, combined with the energy storage and the energy storage cost at the beginning of the calculation period. After the proportion of the energy storage source in each calculation period is obtained by iteration, the energy storage cost in the energy storage system at the end of the calculation period can be obtained by iteration combined with the energy storage cost at the beginning of the calculation period. The energy storage cost is used as an optimization index of the energy storage system for optimization control. Since the energy storage cost is determined according to the proportion of the energy storage source determined by the charging and discharging operation, the more accurate energy storage cost calculation result can be obtained by combining the historical charging and discharging operation, thereby helping to reliably reduce the energy storage system cost and improve the energy storage system benefit.

[0007] In combination with the first aspect, in a first possible implementation manner of the first aspect, determining the proportion of the energy storage source in the divided calculation period includes: determining a first energy supply of the power generation device in the calculation period, and determining a second energy supply of the power grid in the calculation period; and determining the proportion of the energy storage source in the calculation period according to the proportion of the first energy supply, the second energy supply and total energy supply in the calculation period.

[0008] When predicting the proportion of the energy storage source in the calculation period, the proportion of the energy storage source in the calculation period can be determined according to the size of the energy provided by the power generation device and the power grid, i.e. the first energy supply and the second energy supply. For example, in the calculation period, the first energy supply of the power generation device is E1, and the second energy supply of the power grid is E2, and then the proportion of the power generation device in the calculation period is E1 / (E1+E2), and the proportion of the power grid is E2 / (E1+E2).

[0009] In combination with the first aspect, in a second possible implementation manner of the first aspect, determining the proportion of the energy storage source in the divided calculation period includes: determining a first energy storage of the power generation device in the calculation period, and determining a second energy storage of the power grid in the calculation period; and determining the proportion of the energy storage source in the calculation period according to the first energy storage, the second energy storage and total energy storage in the calculation period.

[0010] Since the proportion of the power provided by the power generation device and consumed by the power grid is affected by the priority of the power consumed by the load, the proportion of the energy storage source can be determined by the increase value of the energy storage of the energy storage device and the source of the increase value of the energy storage. For example, the first energy storage provided by the power generation device is E3, and the second energy storage provided by the power grid is E4, and the proportion of the energy storage source can be represented as: the proportion of the energy storage of the power generation device = E3 / (E3+E4), and the proportion of the energy storage of the power grid = E4 / (E3+E4).

[0011] In a third possible implementation manner of the first aspect, in the case that the power provided by the power generation device is consumed by the load in priority, the first energy storage provided by the power generation device in the calculation period is determined, including: when there is energy storage charging and the power provided by the power generation device is less than or equal to the power consumed by the load, the first energy storage provided by the power generation device is zero; when there is energy storage charging and the power provided by the power generation device is greater than the power consumed by the load, the first energy storage provided by the power generation device is the smaller value of the remaining power of the power generation device and the increase value of the energy storage in the calculation period, the remaining power of the power generation device being the difference between the power provided by the power generation device and the power consumed by the load.

[0012] In the case that the power provided by the power generation device is consumed by the load in priority, if the power provided by the power generation device is less than or equal to the power consumed by the load, the power generation device does not provide energy storage for the energy storage device, and the first energy storage is zero. If the power provided by the power generation device is greater than the power consumed by the load, the first energy storage can be determined based on the difference between the power provided by the power generation device and the power consumed by the load, i.e., the remaining power of the power generation device. Considering that the photovoltaic power generation device has a non-consumed condition, the smaller value of the remaining power of the power generation device and the increase value of the energy storage can be selected as the first energy storage.

[0013] In a fourth possible implementation manner of the first aspect, in the case that the power provided by the power generation device is consumed by the load in priority, the second energy storage provided by the power grid in the calculation period is determined, including: when there is energy storage charging and the power provided by the power generation device is less than the power consumed by the load, the second energy storage is determined according to the power provided by the power generation device, the power consumed by the load and the power provided by the power grid; when there is energy storage charging and the power provided by the power generation device is greater than or equal to the power consumed by the load, the second energy storage is determined according to the power provided by the power grid.

[0014] In the case that the load preferentially uses the power provided by the power generation device, if the power provided by the power generation device is less than or equal to the power consumed by the load, the second energy storage amount can be obtained by subtracting the load from the sum of the power grid and the power provided by the power generation device. If the power provided by the power generation device is greater than the power consumed by the load, the second energy storage amount can be determined according to the difference between the power provided by the power generation device and the power consumed by the load.

[0015] With reference to any one of the first aspect to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, before determining the energy storage source proportion in the divided calculation period, the method further includes: determining a proportion of the installed capacity of the power generation device in total energy supply; and determining a manner of calculating the energy storage source proportion according to the proportion of the installed capacity of the power generation device in total energy supply.

[0016] Based on the proportion of the installed capacity of the power generation device, the manner of calculating the energy storage source proportion can be determined accordingly, so as to effectively simplify the calculation and improve the determination efficiency of the energy storage source proportion. The installed capacity of the power generation device indirectly affects the system benefit by affecting the power load characteristics of the user.

[0017] With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, the manner of calculating the energy storage source proportion according to the proportion of the installed capacity of the power generation device in total energy supply includes: when the proportion of the installed capacity is less than a first proportion threshold, the energy storage source proportion is determined by preferentially consuming the power provided by the power generation device; and when the proportion of the installed capacity is greater than or equal to the first proportion threshold, the energy storage source proportion is determined by energy supply.

[0018] The size of the energy storage proportion of the power generation device is determined by the size of the installed capacity of the power generation device. When the energy storage proportion is small, for example, the proportion of the installed capacity in total energy supply is less than a first proportion threshold, the energy storage source proportion can be determined by preferentially consuming the power of the power generation device. When the proportion of the installed capacity in total energy supply is greater than or equal to the first proportion threshold, the energy storage source proportion is determined by energy supply.

[0019] With reference to any one of the first aspect to the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the energy storage cost in the energy storage system is determined according to the energy storage source proportion, including: determining an energy storage discharge benefit in the calculation period, and determining a charging cost of charging by the power grid in the calculation period; and updating a unit energy cost stored in the energy storage system according to the energy storage discharge benefit and the charging cost.

[0020] In a new calculation period, a charging cost and a discharging benefit are generated, the charging cost can be determined according to the power provided by the mains, and the discharging benefit can be determined according to the discharging amount, the discharging time and the time-of-use electricity price of the power consumption of the energy storage system. According to the discharging benefit and the energy storage cost, the energy storage cost can be updated.

[0021] With reference to the seventh possible implementation manner of the first aspect, in an eighth possible implementation manner of the first aspect, according to the energy storage discharging benefit and the charging cost, the unit energy cost stored in the energy storage system is updated, including: determining the energy storage cost at the end time of the calculation period according to the energy storage cost at the start time of the current calculation period, the energy storage discharging benefit in the calculation period and the charging cost in the calculation period; and updating the unit energy cost of the energy storage system according to the energy storage cost at the end time of the calculation period and the energy stored in the energy storage system.

[0022] When the energy storage cost is updated according to the discharging benefit and the charging cost, the unit energy cost can be updated. For example, the unit energy cost can be the pool-in kWh cost. The pool-in kWh cost can be the cost of each kWh of the energy stored in the energy storage battery. When the pool-in kWh cost is calculated, the energy storage cost at the end time of the calculation period can be determined according to the pool-in kWh cost at the start time of the calculation period, in combination with the energy storage discharging benefit in the calculation period and the charging cost in the calculation period, and the pool-in kWh cost can be determined according to the ratio of the energy storage cost to the energy storage. For example, the energy storage cost at the end time of the first calculation period can be determined according to the charging cost in the first calculation period. The energy storage cost at the end time of the Nth calculation period can be determined according to the charging cost in the Nth calculation period and the energy storage cost at the start time of the Nth calculation period, which is the end time of the (N-1)th calculation period. In this way, the energy storage cost at the end time of the Nth calculation period can be determined according to the charging cost in the Nth calculation period and the energy storage cost at the start time of the Nth calculation period, which is the end time of the (N-1)th calculation period. Therefore, the energy storage cost at the end time of any calculation period can be updated by iteratively updating the charging cost of the historical charging and discharging operation. The energy of the power generation device for power generation can include renewable energy affected by weather, or can include non-renewable energy. The renewable energy includes, for example, light energy or wind energy.

[0023] With reference to the seventh possible implementation manner of the first aspect, in a ninth possible implementation manner of the first aspect, after the energy storage discharging benefit in the calculation period is determined, the method further includes: determining the total benefit of the energy storage system in the calculation period according to the energy storage discharging benefit in the calculation period, in combination with the accommodation benefit of the power generation device and the surplus generation on-grid benefit.

[0024] The total income in the calculation period is determined by the photovoltaic consumption income, the photovoltaic surplus grid-connected income and the energy storage discharge income, so that the income of each calculation period can be accurately obtained, and the total income of the energy storage system can be obtained based on the determined income of each calculation period. Through optimization of the income measurement, the accuracy of the calculated income is higher.

[0025] The second aspect of the embodiments of the present application provides a control device of an energy storage system, the device comprising: an energy storage source proportion determination unit configured to determine an energy storage source proportion in a divided calculation period according to the divided calculation period; a cost determination unit configured to determine an energy storage cost in the energy storage system according to the energy storage source proportion; and a dynamic control unit configured to perform optimized control on the energy storage system according to the energy storage cost.

[0026] In combination with the second aspect, in a first possible implementation manner of the second aspect, the energy storage source proportion determination unit comprises: a power supply prediction subunit configured to determine a first power supply provided by a power generation device in the calculation period, and determine a second power supply through a commercial power in the calculation period; and a first energy storage source proportion determination subunit configured to determine the energy storage source proportion in the calculation period according to a proportion of the first power supply, the second power supply and a total power supply in the calculation period.

[0027] In combination with the second aspect, in a second possible implementation manner of the second aspect, the energy storage source proportion determination unit comprises: an energy storage amount determination subunit configured to determine a first energy storage amount provided by a power generation device in the calculation period, and determine a second energy storage amount provided by a commercial power in the calculation period; and a second energy storage source proportion determination subunit configured to determine the energy storage source proportion in the calculation period according to the first energy storage amount, the second energy storage amount and a total energy storage amount in the calculation period.

[0028] In combination with the second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, in the case that the power provided by the power generation device is preferentially consumed by the load, the energy storage amount calculation subunit comprises: a first calculation module configured to, when there is energy storage charging and the power provided by the power generation device is less than or equal to the power consumed by the load, the first energy storage amount provided by the power generation device is zero; and a second calculation module configured to, when there is energy storage charging and the power provided by the power generation device is greater than the power consumed by the load, the first energy storage amount provided by the power generation device is a smaller value of a residual power of the power generation device and an energy storage increase value in the calculation period, the residual power of the power generation device being a difference between the power provided by the power generation device and the power consumed by the load.

[0029] In a fourth possible implementation manner of the second aspect, in the case that the power provided by the power generation device is preferentially consumed by the load, the energy storage amount prediction subunit comprises: a third calculation module configured to determine the second energy storage amount according to the power provided by the power generation device, the power consumed by the load and the power provided by the commercial power when there is energy storage charging and the power provided by the power generation device is less than the power consumed by the load; and a fourth calculation module configured to determine the second energy storage amount according to the power provided by the commercial power when there is energy storage charging and the power provided by the power generation device is greater than or equal to the power consumed by the load.

[0030] In a fifth possible implementation manner of the second aspect, the device further comprises: an installed capacity proportion determination unit configured to determine a proportion of the installed capacity of the power generation device in the total power supply amount; and a mode determination unit configured to determine a mode of calculating the energy storage source proportion according to the proportion of the installed capacity of the power generation device in the total power supply amount.

[0031] In a sixth possible implementation manner of the second aspect, the mode determination unit comprises: a first selection subunit configured to determine the energy storage source proportion by the mode of preferentially consuming the power provided by the power generation device when the proportion of the installed capacity is less than a first proportion threshold; and a second selection subunit configured to determine the energy storage source proportion by the power supply amount when the proportion of the installed capacity is greater than or equal to the first proportion threshold.

[0032] In a seventh possible implementation manner of the second aspect, the cost determination unit comprises: a benefit cost determination subunit configured to determine a benefit of discharging the energy storage in the calculation period and determine a charging cost of charging the energy storage by the commercial power in the calculation period; and a cost updating subunit configured to update the unit power cost stored in the energy storage system according to the benefit of discharging the energy storage and the charging cost.

[0033] In an eighth possible implementation manner of the second aspect, the cost updating subunit comprises: a first energy storage cost calculation module configured to determine an energy storage cost at an end time of the calculation period according to an energy storage cost at a start time of the calculation period, the benefit of discharging the energy storage in the calculation period and the charging cost in the calculation period; and a system cost calculation module configured to update the unit power cost of the energy storage system according to the energy storage cost at the end time of the calculation period in combination with the power stored in the energy storage system.

[0034] With reference to the seventh possible implementation manner of the second aspect, in a ninth possible implementation manner of the second aspect, after determining the energy storage discharge benefit in the calculation period, the method further comprises: determining, according to the energy storage discharge benefit in the calculation period, a total benefit of the energy storage system in the calculation period in combination with a power generation device accommodation benefit and a power generation device excess amount of generation on-grid benefit.

[0035] The third aspect of the embodiments of the present application provides an energy storage system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method according to any one of the first aspect when executing the computer program.

[0036] The fourth aspect of the embodiments of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the method according to any one of the first aspect.

[0037] It can be understood that the beneficial effects of the second aspect to the fifth aspect described above can refer to the related description of the first aspect described above, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0039] Figure 1 is an implementation scenario diagram of an energy storage system control method provided by the embodiments of the present application;

[0040] Figure 2 is an implementation flow diagram of an energy storage system control method provided by the embodiments of the present application;

[0041] Figure 3 is an implementation flow diagram of updating unit electric energy cost provided by the embodiments of the present application;

[0042] Figure 4 is a calculation process diagram of unit electric energy cost provided by the embodiments of the present application;

[0043] Figure 5 is a typical control scenario diagram of an energy storage system provided by the embodiments of the present application;

[0044] Figure 6 is a control device diagram of an energy storage system provided by the embodiments of the present application;

[0045] Figure 7 FIG. 1 is a schematic diagram of an energy storage system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0046] In the following description, for the purposes of explanation and not limitation, specific details are set forth, such as particular sequences of acts, in order to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and circuits are omitted so as not to obscure the description of the present application with unnecessary detail.

[0047] In order to illustrate the technical solutions described in the present application, the following will be described through specific embodiments.

[0048] The energy storage system includes a photovoltaic energy storage combined power supply system and a wind power energy storage combined power supply system, etc. The energy storage system can store the electric energy generated by the power generation equipment, such as photovoltaic power generation equipment or wind power generation equipment, and release it at an appropriate time. In the context of energy shortage, the photovoltaic energy storage system has been widely used. The energy storage system relying on light energy, wind energy and other power generation equipment can effectively alleviate the intermittency and instability of photovoltaic power generation or wind power generation, and through the peak clipping and valley filling control mode, the electricity cost of access to the power grid can be effectively reduced.

[0049] However, the power generation characteristics of the photovoltaic, wind power and other new energy power generation systems have strong timeliness, and the electricity prices in most areas also have time sequence characteristics. Based on the traditional "two charging and two discharging", that is, charging in the period of lower electricity price and more power generation, and discharging in the period of higher electricity price and less power generation, the control mode does not fully consider the cost and benefit generated by the historical charging and discharging of the historical energy storage system, which is not conducive to accurately obtaining the cost and benefit of the energy storage system, and is not conducive to more effective control of the energy storage system.

[0050] Based on this, an embodiment of the present application provides a control method of an energy storage system, as shown in Figure 1The control method of the energy storage system is shown in the corresponding energy storage power supply system topology diagram. The power generation equipment in this implementation scenario is a light energy power generation equipment, and the system topology diagram includes m photovoltaic devices, n loads, an energy storage device, and a city grid incoming line. The photovoltaic devices are photovoltaic 1, photovoltaic 2, photovoltaic 3, …, and photovoltaic m, respectively. The loads are load 1, load 2, load 3, …, and load n, respectively. An electric meter is arranged at the connection between each load, photovoltaic device, and low-voltage bus for collecting the power generated or consumed. For example, a photovoltaic electric meter (photovoltaic electric meter 1, photovoltaic electric meter 2, photovoltaic electric meter 3, …, and photovoltaic electric meter m) is arranged at the connection between the photovoltaic device and the low-voltage bus. A load electric meter (load electric meter 1, load electric meter 2, load electric meter 3, …, and load electric meter n) is arranged at the connection between the load and the low-voltage bus. An energy storage electric meter is arranged at the connection between the energy storage device and the low-voltage bus for collecting the power charged and discharged by the energy storage device. An incoming line electric meter is arranged at the connection between the city grid incoming line and the low-voltage bus for collecting the power provided by the city power for the energy storage power supply system. The controller can read the power collected by each electric meter, determine the energy storage source proportion in the energy storage system based on the divided calculation period, determine the energy storage cost based on the energy storage source proportion, calculate the price difference of the energy storage charging and discharging through the energy storage cost, and calculate the income of the energy storage system in a certain time period, and control the working state of the load, the energy storage system, and the photovoltaic device based on the energy storage cost or income.

[0051] Figure 2 The implementation flowchart of the control method of the energy storage system provided in the embodiments of the present application is shown in the following detailed description:

[0052] In S201, the energy storage source proportion in the divided calculation period is determined according to the divided calculation period.

[0053] The calculation period in the embodiments of the present application can be determined according to the transformation period of the time-of-use electricity price. For example, the minimum value of the transformation period of the time-of-use electricity price is 1 hour, and the calculation period can be set to 1 hour. Alternatively, it can be set to less than 1 hour and a value obtained by dividing 1 hour, such as 0.5 hours.

[0054] According to the divided calculation period, the income and cost in each calculation period can be calculated, and the influence of the historical charging and discharging and photovoltaic power generation on the cost can be accurately obtained based on the superposition of the calculation periods, so that the cost calculation can be accurately performed.

[0055] Since the power generation costs of the power generation sources in the system are different, in order to calculate the charging cost of the energy storage system in the calculation period, the application proposes the concept of energy storage source proportion. The energy storage source proportion can calculate the charging proportion of each power generation source in the energy storage charging amount according to the energy distribution of the power system, and use the energy storage source proportion and the charging amount in the calculation period, so as to accurately calculate the charging cost of the energy storage in a certain period.

[0056] In general, the power balance formula of the energy storage system is:

[0057] P 市网 =P 负载 —P 发电设备 ±P 储能

[0058] Wherein, P 市网 is the incoming power of the power grid, P 负载 is the power consumption of the load, P 发电设备 is the power generation of the power generation equipment, and P 储能 is the charging power or discharging power of the energy storage system.

[0059] There will be a charging cost when the energy storage system is charging. Since the system has two power supply sides of the power grid and the power generation equipment, the application introduces the energy storage source proportion η as an index to distinguish the two different sources of electric energy, so as to more accurately determine the charging cost.

[0060] In possible implementation manners, the energy storage source proportion can be determined based on the energy supply. The first energy supply provided by the power generation equipment in the calculation period and the second energy supply provided by the power grid in the calculation period can be determined, and the energy storage source proportion is determined based on the ratio of the first energy supply to the total energy supply and the ratio of the second energy supply to the total energy supply.

[0061] For example, for any calculation period, the power generation equipment provides the first energy supply E1, and the power grid provides the second energy supply E2, and the energy storage source proportion determined based on the first energy supply E1 and the second energy supply E2 is:

[0062]

[0063]

[0064] Wherein, η 发电设备-＞储能 represents the proportion of energy storage charging by the power generation equipment, η 市电-＞储能 represents the proportion of energy storage charging by the power grid, and E1+E2 represents the total energy supply in the calculation period.

[0065] When the power generation equipment is a photovoltaic device, E1 can represent the electrical energy provided by the photovoltaic device. When the power generation equipment is a wind power device, E1 can represent the electrical energy provided by the wind power device. When the power generation equipment is a photovoltaic device and a wind power device, E1 can represent the electrical energy provided by the wind power device and the solar power device.

[0066] In a possible implementation, the proportion of energy storage sources may also be determined based on a setting that the electric energy provided by the power generation equipment is consumed first.

[0067] Under the premise that power generation equipment is consumed first, the load consumes the power it provides first. Based on the amount of power consumed by the load and the power generated by the power generation equipment, the first amount of energy storage provided by the power generation equipment to the energy storage system and the second amount of energy storage provided by the mains can be determined on a case-by-case basis. Based on the determined first and second energy storage amounts, combined with the total energy storage determined by the sum of the first and second energy storage amounts, the energy storage source ratio is calculated.

[0068] When the electric energy provided by the power generation equipment is consumed by the load first, the first storage energy E3 provided by the power generation equipment to the energy storage system can be expressed as:

[0069]

[0070] Among them, E 储能充电 Indicates the energy storage system's storage capacity during the calculation period, E 发电设备 Indicates the electrical energy generated by the power generation equipment, E 负载 Indicates the electrical energy consumed by the load during this calculation period.

[0071] The above formula shows that when the power provided by the power generation equipment is consumed by the load first, if there is energy storage charging (i.e. E 储能充电 is greater than 0), and the electric energy generated by the power generation equipment is less than the electric energy consumed by the load, since the power generation equipment is completely consumed by the load, the electric energy provided to the energy storage system by the power generation equipment is 0.

[0072] When the power provided by the power generation equipment is preferentially consumed by the load, if there is energy storage charging, and the power generated by the power generation equipment is greater than (or may be equal to) the power consumed by the load, the first storage capacity can be determined based on the difference between the power generated by the power generation equipment and the power consumed by the load. Taking into account the situation where the power generation equipment is consumed, the smaller value of the difference and the energy storage system's storage capacity during the calculation cycle can be selected as the first storage capacity, thereby improving the accuracy of the first storage capacity result.

[0073] If there is no energy storage charging, that is, E 储能充电 If it is less than or equal to 0, the first energy storage capacity is 0.

[0074] In the determination of the second energy storage, if the power provided by the power generation device is less than the power consumed by the load, the second energy storage can be represented as: E4=E 市电 +E 发电设备 —E 负载 That is, the second energy storage is obtained by subtracting the load from the sum of the power provided by the power grid and the power provided by the power generation device.

[0075] If the power provided by the power generation device is greater than the power consumed by the load, the power provided by the power grid can directly pass through the incoming line meter to read the second energy storage. That is, the second energy storage is the total power provided by the power grid incoming line, that is, the total power provided by the power grid.

[0076] After determining the first energy storage E3 and the second energy storage E4, the total energy storage (E3+E4) in the calculation period can be obtained according to the sum of the first energy storage E3 and the second energy storage E4. According to the ratio of the first energy storage to the total energy storage and the ratio of the second energy storage to the total energy storage, the proportion of the energy storage source of different power supply parties can be determined.

[0077] For example, the proportion of the energy storage source supplied by the power generation device can be represented as:

[0078]

[0079] The proportion of the energy storage source supplied by the power grid can be represented as:

[0080]

[0081] In the embodiments of the present application, the way of determining the proportion of the energy storage source can be flexibly selected according to the size of the installed capacity proportion of the power generation device. For example, the proportion of the energy storage source can be determined according to the installed capacity proportion, including the proportion of the installed capacity of the power generation device in the total energy supply, or the ratio relative to the incoming line capacity (power supply by the power grid).

[0082] For example, in the case that the installed capacity of the power generation device (including, for example, photovoltaic devices or wind power devices) is large and the installed capacity proportion is greater than a first proportion threshold, the proportion of the energy storage source is determined by the energy supply. In the case that the installed capacity proportion of the power generation device is small, for example, less than or equal to the first proportion threshold, the proportion of the energy storage source can be determined by setting the power provided by the power generation device to be consumed by the load in priority.

[0083] The first proportion threshold can be any value in the range of 20%-40%, such as 20%, 25%, 30%, 35% or 40%, etc.

[0084] In S202, the energy storage cost in the energy storage system is determined according to the proportion of the energy storage source.

[0085] The energy storage cost in the energy storage system can be understood as the cost of the stored electric energy in the energy storage system or the energy storage device. After determining the energy storage source proportion, the energy storage cost can be updated and calculated based on the energy storage source because the costs of energy supply from different sources are different.

[0086] To simplify the calculation of the energy storage cost, the present application embodiment proposes a concept of unit electric energy cost. The unit electric energy cost can include the intra-pool degree electric cost or the cost of other set electric energy values. The intra-pool degree electric cost is the average cost of each degree of electric energy stored in the battery. For example, the energy stored in the energy storage system, i.e., the electric energy stored in the battery, can be sourced from the power generation device, and the cost thereof can be set to 0 (the actual cost can be determined according to the renewable energy or non-renewable energy used for power generation), or can be sourced from the mains supply, and the cost thereof is associated with the electricity price at the time of power supply. By calculating the ratio of the total cost of the stored electric energy to the total electric energy, the intra-pool degree electric cost can be obtained. Through the calculation of the unit electric energy cost, the average electricity price of the electric energy stored in the energy storage system can be determined according to the charging and discharging in the calculation period and the real-time electricity price, i.e., the historical data is considered and the calculation method is simplified.

[0087] When the energy storage cost at the end time of the calculation period is determined, the energy storage cost of the energy storage system can be determined according to the discharging income and the charging cost, as shown in the following formula: Figure 3 The process can include the following steps:

[0088] In S301, the discharging income of the energy storage system in the calculation period is calculated.

[0089] Suppose the discharging amount of the energy storage system in the Xth calculation period is E d , and the intra-pool degree electric cost is P s (X), then the discharging income generated by the energy storage system in the calculation period is:

[0090] R ess_discharge = P s (X) × E d

[0091] R ess_discharge represents the discharging income generated by the energy storage system in the calculation period.

[0092] In S302, the charging cost of the energy storage system in the calculation period is calculated.

[0093] Suppose the charging amount of the energy storage system in the calculation period is E c , the time-of-use electricity price in the calculation period is P r (X), and the energy storage source proportion of the mains in the energy storage system is η 市电->储能 , then the charging cost R ess_charge in the calculation period can be represented as:

[0094] R ess_charge =P r (X)×E c ×η 市电->储能

[0095] In the calculation of the charging cost, if the power generation equipment is a renewable energy-based power generation equipment, the cost of the proportion of the electric energy provided by the power generation equipment is 0 by default, and only the cost brought by the commercial power needs to be considered.

[0096] In S303, the unit electric energy cost is updated according to the discharge income and the energy storage cost.

[0097] After the calculated discharge income and the charging cost are calculated, the discharge income and the charging cost in the calculation period can be iterated to the unit electric energy cost at the beginning of the calculation period to obtain the unit electric energy cost at the end of the calculation period.

[0098] For example, the end time of the calculation period is the X+1 time, and the beginning time of the calculation period is the X time, and the unit electric energy cost at the X+1 time can be expressed as:

[0099]

[0100] Wherein, P s (X+1) represents the unit electric energy cost of the electric energy stored in the energy storage system at the X+1 time, i.e. the end time of the Xth calculation period, Es(X) is the stored electric energy at the X time (the beginning time of the Xth calculation period), the discharge amount in the Xth calculation period is E d , the charging amount of the energy storage system in the Xth calculation period is E c , the proportion of the commercial power in the energy storage source in the energy storage system in the Xth calculation period is η 市电->储能 , and the time-of-use electricity price in the Xth calculation period (the calculation period determined by the X time and the X+1 time) is P r (X).

[0101] According to the above formula, the unit electric energy cost at the X+1 time is calculated according to the unit electric energy cost at the X time, the total price of the stored electric energy at the X+1 time, and the average electric energy of the energy storage system, i.e. the unit electric energy cost, such as the degree electric energy cost in the pool.

[0102] As Figure 4 shown is a schematic diagram of the calculation process of the unit electric energy cost. As Figure 4 shown in a graph, at the X time, the electric energy or electric quantity stored in the energy storage system is E s (X), and the unit electric energy cost at this time is P s (X). As Figure 4As shown in Figure b, in the Xth calculation cycle, the energy discharged by the energy storage system is E d , the electric energy used to charge the energy storage system through the power generation equipment and the mains is Ec. After the charge and discharge process, Figure 4 As shown in Figure c, the electrical energy stored in the energy storage system is E s (X+1), at this time, the total cost of the electric energy stored at time X+1 can be calculated based on the discharge benefit, charging cost, and the cost of the electric energy stored by the energy storage system at time X: (E s (X)-E d )×P s (X)+P r (X)×E c ×η 市电->储能 The unit electricity cost at time X+1 can be obtained by the ratio of the total cost at time X+1 to the electricity at time X+1.

[0103] In a possible implementation, the embodiment of the present application can further determine the total revenue within the calculation period. For example, the total revenue within the calculation period can be obtained based on the consumption revenue of the power generation equipment, the revenue from the grid connection of the surplus power generation, and the revenue from energy storage discharge within the calculation period, which can be expressed as:

[0104] R(X:X+1)=E pv1 ×P r (X)+E pv2 ×P g (X)+(P s (X)×E a -P r (X)×E c ×η 市电->储能 )

[0105] Among them, E pv1 is the photovoltaic power consumption during the calculation period, and E pv2 They represent the photovoltaic surplus grid-connected power in the calculation period. The cost of electricity in the pool at time X is P s (X), the time-of-use electricity price P within the Xth calculation period (i.e., from the Xth time to the X+1th time) r (X), the surplus on-grid electricity price P in the Xth calculation cycle g (X), the discharge amount (or charging energy) in the Xth calculation cycle is E d , the charge amount (or charging energy) in the Xth calculation cycle is E c .

[0106] According to the above-mentioned revenue calculation method, the revenue of the energy storage system can be updated through iterative calculation. The stored energy and unit energy cost of the energy storage system can be initialized. Based on the stored energy and unit energy cost at the initialization (i.e., moment 1), combined with the charging cost and discharge revenue during the first calculation cycle, the stored energy and unit energy cost of the stored energy at moment 2 can be determined. Furthermore, the total revenue for the first calculation cycle can be determined based on the energy storage discharge revenue, the power generation equipment's absorption revenue, and the revenue from the grid access of surplus power. At moment 3, the stored energy and unit energy cost of the stored energy at moment 2 can be calculated based on the stored energy and unit energy cost of the stored energy, combined with the discharge amount and discharge revenue, and the charge amount and charging cost. The revenue for the second calculation cycle is calculated based on the discharge revenue during the second calculation cycle. The total revenue can be accumulated by adding the revenue from the first calculation cycle and the revenue from the second calculation cycle.

[0107] According to the above calculation method, the stored energy and unit energy storage cost of the energy storage system at time i can be used to calculate the stored energy at time i+1 and the unit energy storage cost at time i+1. The revenue for the calculation period from time i to time i+1 can then be calculated. The total revenue for time i+1 can be calculated based on the total revenue before time i and the revenue during the i-th calculation period. Here, i is a natural number greater than 1.

[0108] In S203, the energy storage system is optimized and controlled according to the energy storage cost.

[0109] Based on the above calculation results, the energy storage cost at any time can be obtained. Based on the energy storage cost as the optimization target, combined with the predicted load information and power generation equipment information, a target optimization algorithm can be used, including gradient descent, stochastic gradient descent algorithm, small batch stochastic gradient descent algorithm, genetic algorithm, particle swarm algorithm, etc., to adjust or control the adjustable parameters in the energy storage system, including charging and discharging strategies, energy storage capacity, load management and other parameters, so as to minimize the energy storage cost of the energy storage system.

[0110] Alternatively, the total benefit determined by the energy storage cost can be used as the optimization target, and a target optimization algorithm, such as gradient descent or stochastic gradient descent algorithm, can be used to adjust or control the adjustable parameters in the energy storage system, including charging and discharging strategies, energy storage capacity, load management and other parameters, so as to maximize the total benefit of the energy storage system.

[0111] Figure 5 A typical control scenario diagram of an energy storage system provided in an embodiment of the present application is shown in FIG. Figure 5As shown, the load device, the power generation device and the energy storage device can collect power consumption data, power generation data or charge and discharge data through the electric meter, and interact with the Internet of Things platform. The Internet of Things platform is connected with the energy management system (in a possible implementation manner, the electric meter can also be directly connected with the energy management system). The energy management system stores historical data (including, for example, the electrical energy stored by the energy storage system, and the unit electrical energy cost of the energy storage system), electrical energy statistical calculation, and the function of interacting with the AI platform. The AI platform can analyze and calculate the data, generate prediction data of the load and the photovoltaic, and based on a target optimization algorithm, issue an optimal control strategy to optimize the control of the energy storage power supply system.

[0112] In a possible implementation manner, the analysis and calculation, the generation of prediction data of the load and the photovoltaic, and the issuance of the optimal control strategy based on the target optimization algorithm can also be directly performed by the energy management system.

[0113] Based on the historical unit electrical energy cost, the charging cost and the discharging benefit in the calculation period are combined to update the unit electrical energy cost, so that the influence of the historical charge and discharge event on the energy storage system can be reflected in the unit energy storage cost, thereby obtaining more accurate cost results and further obtaining more accurate benefit results.

[0114] It should be understood that the size of the serial number of each step in the above embodiments does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0115] Figure 6 A structural schematic diagram of a control device of an energy storage system provided by the embodiments of the present application is shown, and the device comprises:

[0116] An energy storage source proportion determination unit 601 is configured to determine an energy storage source proportion in the divided calculation period according to the divided calculation period;

[0117] A cost determination unit 602 is configured to determine an energy storage cost in the energy storage system according to the energy storage source proportion;

[0118] A dynamic control unit 603 is configured to perform optimization control on the energy storage system according to the energy storage cost.

[0119] Figure 6 The control device of the energy storage system shown corresponds to the control method of the energy storage system shown. Figure 2

[0120] Figure 7 A schematic diagram of an energy storage system provided by the embodiments of the present application is shown. As shown in the figure, Figure 7 ​As shown, the energy storage system 7 of the embodiment includes a processor 70, a memory 71, and a computer program 72 stored in the memory 71 and capable of running on the processor 70, for example, a control program of the energy storage system. The processor 70 implements the steps in each of the above-described energy storage system control method embodiments when executing the computer program 72. Alternatively, the processor 70 implements the functions of each module / unit in each of the above-described device embodiments when executing the computer program 72.

[0121] For example, the computer program 72 can be divided into one or more modules / units stored in the memory 71 and executed by the processor 70 to complete the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 72 in the energy storage system 7.

[0122] The energy storage system 7 can be a desktop computer, a notebook, a palm computer, a cloud server, and other computing devices. The energy storage system can include, but is not limited to, the processor 70 and the memory 71. Those skilled in the art can understand that the energy storage system can further include other components, for example, the energy storage system can further include an input / output device, a network access device, a bus, and the like. Figure 7 The energy storage system 7 is only an example and does not constitute a limitation on the energy storage system 7, and can include more or fewer components than those shown, or combine certain components, or different components, for example, the energy storage system can also include an input / output device, a network access device, a bus, and the like.

[0123] The processor 70 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic components, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0124] The memory 71 can be an internal storage unit of the energy storage system 7, for example, a hard disk or a memory of the energy storage system 7. The memory 71 can also be an external storage device of the energy storage system 7, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the energy storage system 7. Further, the memory 71 can also include both the internal storage unit and the external storage device of the energy storage system 7. The memory 71 is used to store the computer program and other programs and data required by the energy storage system. The memory 71 can also be used to temporarily store data that has been output or will be output.

[0125] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit, and the integrated unit can be realized in the form of hardware or software. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the application. The specific working process of the units and modules in the system can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0126] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can refer to the relevant description of other embodiments.

[0127] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the application.

[0128] In the embodiments of the present application, it should be understood that the disclosed apparatus / terminal device and method can be implemented in other manners. For example, the described apparatus / terminal device embodiments are merely schematic. For example, the division of the modules or units is merely logical function division. There can be another division manner for actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, can be indirect couplings or communication connections through some interfaces, devices or units.

[0129] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0130] In addition, each functional unit in the various embodiments of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0131] The integrated module / unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, all or part of the flow of the above-mentioned embodiment methods can also be completed by computer program instruction related hardware, and the computer program can be stored in a computer readable storage medium. When the processor executes the computer program, the steps of each method embodiment described above can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable file or some intermediate form. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the computer readable medium can include appropriate contents according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electric carrier signal and telecommunication signal.

[0132] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A control method of an energy storage system, characterized by, The method comprises: According to the divided calculation period, the proportion of energy storage sources in the divided calculation period is determined; According to the proportion of energy storage sources, the energy storage cost in the energy storage system is determined; According to the energy storage cost, the energy storage system is optimized and controlled.

2. The method of claim 1, wherein, Determination of the proportion of energy storage sources in the divided calculation period comprises: Determine the first energy supply of the power generation equipment in the calculation period, and determine the second energy supply through the mains in the calculation period; According to the proportion of the first energy supply, the second energy supply and the total energy supply in the calculation period, the proportion of energy storage sources in the calculation period is determined.

3. The method of claim 1, wherein, Determination of the proportion of energy storage sources in the divided calculation period comprises: Determine the first energy storage of the power generation equipment in the calculation period, and determine the second energy storage through the mains in the calculation period; According to the first energy storage, the second energy storage and the total energy storage in the calculation period, the proportion of energy storage sources in the calculation period is determined.

4. The method of claim 3, wherein, In the case that the power provided by the power generation equipment is consumed by the load in priority, the first energy storage provided by the power generation equipment in the calculation period is determined, comprising: When there is energy storage charging, and the power provided by the power generation equipment is less than or equal to the power consumed by the load, the first energy storage provided by the power generation equipment is zero; When there is energy storage charging, and the power provided by the power generation equipment is greater than the power consumed by the load, the first energy storage provided by the power generation equipment is the smaller value of the remaining power of the power generation equipment and the energy storage increase value in the calculation period, the remaining power of the power generation equipment is the difference between the power provided by the power generation equipment and the power consumed by the load.

5. The method of claim 3, wherein, In the case that the power provided by the power generation equipment is consumed by the load in priority, the second energy storage provided by the mains in the calculation period is determined, comprising: When there is energy storage charging, and the power provided by the power generation equipment is less than the power consumed by the load, the second energy storage is determined according to the power provided by the power generation equipment, the power consumed by the load and the power provided by the mains; When there is energy storage charging, and the power provided by the power generation equipment is greater than or equal to the power consumed by the load, the second energy storage is determined according to the power provided by the mains.

6. The method according to any one of claims 1 to 5, characterized in that, Before determining the proportion of energy storage sources in the divided calculation period, the method further comprises: Determine the proportion of installed capacity of the power generation equipment in the total energy supply; According to the proportion of installed capacity in the total energy supply, the way to calculate the proportion of energy storage sources is determined.

7. The method of claim 6, wherein, According to the proportion of installed capacity in the total energy supply, the way to calculate the proportion of energy storage sources is determined, comprising: When the proportion of installed capacity is less than the first proportion threshold, the proportion of energy storage sources is determined by the way of consuming the power provided by the power generation equipment in priority; When the proportion of installed capacity is greater than or equal to the first proportion threshold, the proportion of energy storage sources is determined by the energy supply.

8. The method according to any one of claims 1 to 7, characterized in that, According to the proportion of energy storage sources, the energy storage cost in the energy storage system is determined, comprising: Determine the energy storage discharge benefit in the calculation period, and determine the charging cost charged by the mains in the calculation period; According to the energy storage discharge benefit and the charging cost, update the unit energy cost stored in the energy storage system.

9. The method of claim 8, wherein, According to the energy storage discharge benefit and the charging cost, a unit energy cost stored in the energy storage system is updated, including: According to the energy storage cost at the beginning of the current calculation period, the energy storage discharge benefit within the calculation period and the charging cost within the calculation period, the energy storage cost at the end of the calculation period is determined; According to the energy storage cost at the end of the calculation period, the unit energy cost of the energy storage system is updated in combination with the stored energy in the energy storage system.

10. The method of claim 8, wherein, After determining the energy storage discharge benefit within the calculation period, the method further includes: According to the energy storage discharge benefit within the calculation period, the total benefit of the energy storage system within the calculation period is determined in combination with the accommodation benefit of the power generation equipment and the surplus generation on-grid benefit.

11. A control device for an energy storage system, characterized by The device includes: An energy storage source proportion determination unit configured to determine an energy storage source proportion within a divided calculation period according to the divided calculation period; A cost determination unit configured to determine an energy storage cost in the energy storage system according to the energy storage source proportion; A dynamic control unit configured to perform optimization control on the energy storage system according to the energy storage cost.

12. An energy storage system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 10.

13. A computer-readable storage medium storing a computer program, wherein the computer program comprises the following steps of: The computer program is executed by the processor to implement the steps of the method according to any one of claims 1 to 10.

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