Control method and control device of energy storage system and energy storage system

Abstract

The invention discloses a control method and device of an energy storage system and the energy storage system, and relates to the technical field of energy storage control. The energy storage system comprises an energy storage device, a control device, a power grid interface and a cloud end, the energy storage device is electrically connected with the power grid interface and the control device, and the control device is in communication connection with the cloud end. The method comprises the following steps: acquiring fluctuation data of power use of a place to which the energy storage system belongs within a period and operation data of the energy storage device; generating declaration data of a corresponding period according to the fluctuation data and the operation data; and controlling the energy storage device to execute charging and discharging actions in a corresponding period according to the declaration data. The invention aims to improve the economical operation of the energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage control, and in particular to a control method, a control device and an energy storage system. Background Art

[0002] With the advancement of the "dual carbon" policy, renewable energy such as wind power and photovoltaic power is increasing day by day. The fluctuations of these new energy sources have posed a great challenge to the absorption of the power grid. The energy storage system has the characteristics of rapid adjustment, controllability and high reliability. Through frequency regulation, peak shaving and valley filling and other operation strategies, the stability of the power grid can be quickly achieved through charging and discharging. Therefore, more and more local policies require the configuration of energy storage systems on the power generation side to complete the absorption of new energy, so how to achieve the maximum economic operation of energy storage systems is the focus of most new energy manufacturers. At present, the main energy storage operation mode on the market is to obtain profits through peak-valley price differences. The profit model of independent energy storage or virtual power plants mainly participates in transactions in the electricity market. Therefore, how to obtain more benefits through peak-valley price differences as much as possible on the basis of ensuring electricity market transactions is a challenge to achieve the maximum benefits of energy storage. Summary of the invention

[0003] The main purpose of the present invention is to provide a control method for an energy storage system, aiming to improve the economical operation of the energy storage system.

[0004] To achieve the above object, the present invention proposes a control method for an energy storage system, wherein the energy storage system includes an energy storage device, a control device, a power grid interface and a cloud, wherein the energy storage device is electrically connected to the power grid interface and the control device respectively, and the control device is communicatively connected to the cloud, and the method includes:

[0005] Obtaining fluctuation data of power usage in a cycle at the location of the energy storage system and operation data of the energy storage device;

[0006] Generate declaration data of a corresponding period according to the fluctuation data and the operation data;

[0007] The energy storage device is controlled to perform charging and discharging actions within a corresponding period according to the reported data.

[0008] In one embodiment, the step of obtaining the fluctuation data of power usage in a cycle of the energy storage system and the operation data of the energy storage device specifically includes:

[0009] Obtain the peak period, the low period and the stable period of electricity usage in a cycle of the location where the energy storage system belongs;

[0010] Generate fluctuation data within a cycle of the energy storage system according to the peak power consumption period, the valley power consumption period and the stable power consumption period;

[0011] Obtaining the charging rate, discharging rate and electric energy storage ratio of the energy storage device;

[0012] The operation data of the energy storage device is generated according to the charging rate, the discharging rate and the electric energy storage ratio.

[0013] In one embodiment, the specific steps of obtaining the peak period, valley period and stable period of electricity usage in a cycle of the energy storage system include:

[0014] The power situation of the location where the energy storage system is located within a cycle is obtained, and the time period when the power consumption per unit time is greater than the first power consumption is set as the peak power consumption period, the time period when the power consumption per unit time is less than the second power consumption is set as the valley power consumption period, and the time period when the power consumption per unit time is between the first power consumption and the second power consumption is set as the stable power consumption period.

[0015] In one embodiment, the step of generating the declaration data of the corresponding period according to the fluctuation data and the operation data specifically includes:

[0016] According to the fluctuation data, the time period within the cycle is divided into a peak reporting time period, a trough reporting time period and a stable reporting time period;

[0017] According to the operation data, the execution actions of the peak reporting time period, the valley reporting time period and the stable reporting time period are confirmed.

[0018] In one embodiment, the specific steps of confirming the execution actions of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data include:

[0019] According to the operation data and the peak reporting time period, determining whether the peak reporting time period is greater than a first preset time period;

[0020] If the peak reporting time period is greater than a first preset time period, controlling the energy storage device to output electric energy at a first preset discharge rate;

[0021] If the peak reporting time period is less than or equal to the first preset time period, controlling the energy storage device to output electric energy at a second preset discharge rate;

[0022] The second preset discharge rate is greater than the first preset discharge rate.

[0023] In one embodiment, the specific step of confirming the execution action of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data further includes:

[0024] According to the operation data and the peak reporting time period, determining whether the valley reporting time period is greater than a second preset time period;

[0025] If the off-peak reporting time period is greater than the second preset time period, controlling the energy storage device to charge electric energy at a first preset charging rate;

[0026] If the off-peak reporting time period is less than or equal to the second preset time period, controlling the energy storage device to charge electric energy at a second preset charging rate;

[0027] The second preset charging rate is greater than the first preset charging rate.

[0028] In one embodiment, if the off-peak reporting time period is greater than the second preset time period, the step of controlling the energy storage device to charge electric energy at the first preset discharge rate is specifically as follows:

[0029] If the off-peak reporting time period is greater than the second preset time period and is less than or equal to twice the second preset time period, controlling the energy storage device to charge electric energy at a first preset charging rate;

[0030] If the off-peak reporting time period is greater than the second preset time period and greater than twice the second preset time period, the time period in which the off-peak reporting time period is greater than twice the second preset time period is confirmed as the free time period;

[0031] When the free time period is greater than the second preset time length, the peak load benefit in the free time period is confirmed, and a time period in which the peak load benefit is greater than the preset benefit is selected, and the energy storage device is controlled to output electric energy at the second preset discharge rate;

[0032] When the free time period is less than or equal to the second preset time length, the peak load benefit in the free time period is confirmed, and the energy storage device is controlled to output electric energy at a second preset discharge rate.

[0033] In one embodiment, the specific step of confirming the execution action of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data further includes:

[0034] According to the operation data and the fluctuation data, confirm that the time periods before and after the stable reporting time period belong to the peak reporting time period or the valley reporting time period;

[0035] When the first time period of the stable declaration time period is a valley declaration time period and the second time period is a peak time period, determining whether the stable declaration time period is greater than a third preset time length;

[0036] Under the condition that the stable declaration time period is greater than the third preset time period, confirming the peak-shaving benefit of the stable declaration time period, and selecting a time period in which the peak-shaving benefit is greater than the preset benefit, and controlling the energy storage device to charge electric energy at a second preset charging rate;

[0037] Under the condition that the stable declaration time period is less than or equal to the third preset time period, controlling the energy storage device to charge electric energy at a second preset charging rate;

[0038] When the first time period of the stable declaration time period is a peak declaration time period and the second time period is a valley time period, determining whether the stable declaration time period is greater than a third preset time length;

[0039] Under the condition that the stable declaration time period is greater than the third preset time length, confirming the peak-shaving benefit of the stable declaration time period, and selecting a time period in which the peak-shaving benefit is greater than the preset benefit, and controlling the energy storage device to output electric energy at a second preset charging rate;

[0040] Under the condition that the stable declaration time period is less than or equal to the third preset time period, the energy storage device is controlled to output electric energy at a second preset charging rate.

[0041] The present invention also proposes a control device, comprising: a memory, a processor, and a control program for an energy storage system stored in the memory and running on the processor, wherein the control program is configured to implement the steps of a control method for an energy storage system as described in any one of the above items.

[0042] The present invention further provides an energy storage system, which includes the control device and energy storage device, a power grid interface and a cloud as described above.

[0043] The technical solution of the present invention obtains the fluctuation data of electricity usage in a cycle in the area where the energy storage system is located, thereby confirming the usage pattern of the area where the energy storage system is located in a cycle, and judges when the electricity consumption in the area where the energy storage system is located is large, when the electricity consumption is moderate, and when the electricity consumption is low in the cycle, and obtains the electricity price corresponding to each time period in the cycle. Further, by obtaining the operating data of the energy storage device, the amount of electricity stored in the energy storage device and the input and output power are confirmed. By combining the fluctuation data with the operating data, it is confirmed when the energy storage device is charged and when it is discharged, and then the declaration data is confirmed and uploaded to the power trading platform, so that the control device can control the energy storage device to perform corresponding charging and discharging actions in the corresponding time period in the cycle, so as to achieve the effect of improving the economic operation of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0045] Figure 1 A schematic flow chart of a control method for an energy storage system of the present invention;

[0046] Figure 2 A schematic diagram of a flow chart of an embodiment of a control method for an energy storage system of the present invention;

[0047] Figure 3 A schematic flow chart of another embodiment of a control method for an energy storage system of the present invention;

[0048] Figure 4 A schematic flow chart of another embodiment of a control method for an energy storage system of the present invention;

[0049] Figure 5 A schematic diagram of a flow chart of another embodiment of a control method for an energy storage system of the present invention;

[0050] Figure 6 A schematic diagram of a flow chart of another embodiment of a control method for an energy storage system of the present invention;

[0051] Figure 7 A schematic diagram of a flow chart of another embodiment of a control method for an energy storage system of the present invention;

[0052] Figure 8 It is a schematic diagram of the power usage of the energy storage system within one cycle in the control method of the energy storage system of the present invention.

[0053] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0056] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] With the advancement of the "dual carbon" policy, renewable energy such as wind power and photovoltaic power is increasing day by day. The fluctuations of these new energy sources have posed a great challenge to the absorption of the power grid. The energy storage system has the characteristics of rapid adjustment, controllability and high reliability. Through frequency regulation, peak shaving and valley filling and other operation strategies, the stability of the power grid can be quickly achieved through charging and discharging. Therefore, more and more local policies require the configuration of energy storage systems on the power generation side to complete the absorption of new energy, so how to achieve the maximum economic operation of energy storage systems is the focus of most new energy manufacturers. At present, the main energy storage operation mode on the market is to obtain profits through peak-valley price differences. The profit model of independent energy storage or virtual power plants mainly participates in transactions in the electricity market. Therefore, how to obtain more benefits through peak-valley price differences as much as possible on the basis of ensuring electricity market transactions is a challenge to achieve the maximum benefits of energy storage.

[0058] Therefore, reference Figure 1 and Figure 8 The present invention provides a control method for an energy storage system, wherein the energy storage system comprises an energy storage device, a control device, a power grid interface and a cloud, wherein the energy storage device is electrically connected to the power grid interface and the control device respectively, and the control device is communicatively connected to the cloud, and the method comprises:

[0059] Step S100: Acquire fluctuation data of power usage in a period of the energy storage system and operation data of the energy storage device;

[0060] Step S200: generating declaration data of a corresponding period according to the fluctuation data and the operation data;

[0061] Step S300: controlling the energy storage device to perform charging and discharging actions within a corresponding period according to the reported data.

[0062] It should be understood that in the energy storage system, the control device is connected to the cloud through communication, so as to upload the acquired data or the data determined by it to the cloud, so that the cloud can feed back the acquired data to the power trading platform to obtain the confirmation and permission of the power trading platform. The control device will control the energy storage device to perform the corresponding charging and discharging actions in the corresponding time period according to the data fed back to the power trading platform by the cloud the next day, for example, controlling the energy storage device to charge in the first time period and controlling the energy storage device to discharge in the second time period. By confirming that the power trading platform sets different electricity prices for different time periods, and performing corresponding charging and discharging actions in the corresponding time periods, the benefits of the electricity price difference can be obtained. Specifically, when the electricity price is low, the control device controls the energy storage device to charge, that is, to purchase electricity at a lower price; when the electricity price is high, the control device controls the energy storage device to discharge, that is, to output electricity at a higher price, thereby realizing benefits.

[0063] In this embodiment, in order to ensure the maximization of the benefits of the energy storage system and its continuous operation, it is first necessary to obtain the fluctuation data of electricity usage in the area where the energy storage system is located within a period. It is understandable that there are often certain differences in electricity prices in different regions. Specifically, the distribution of natural resources in different regions is different. Some regions are rich in hydropower resources, while others rely on other energy sources such as coal or natural gas. The cost difference of these resources directly affects the cost of power generation, and thus affects the local electricity price. In addition, the electricity prices in different regions are also affected by factors such as supply and demand, and the level of regional economic development. Further, for different regions, the electricity prices in the same time period are also different. For example, in more developed areas, the electricity consumption at night is also at a higher level, while in underdeveloped areas, the electricity consumption at night is at a lower level. This supply and demand relationship will also lead to different electricity prices. Therefore, it is not possible to obtain the fluctuation data of electricity usage in the area where the energy storage system is located within a period. Among them, the setting of the cycle will be set according to the fluctuation data of electricity use in the area where the energy storage system is located and the requirements of the power trading platform. For example, if the daily fluctuation data of the area where the energy storage system is located is within the preset range of changes, and the power trading platform requires the submission of declaration data at least one day in advance, the cycle can be set to one day. For another example, if the weekly fluctuation data of the area where the energy storage system is located is within the preset range of changes, and the power trading platform requires the submission of one week of declaration data, the cycle can be set to one week. Furthermore, the acquisition of fluctuation data can be obtained by the control device or the cloud to facilitate subsequent judgment. In addition, while confirming the fluctuation data of electricity use in the area where the energy storage system is located within a cycle, it is also necessary to confirm the operating data of the energy storage device in order to confirm the maximum storage capacity of the energy storage device, the maximum output power, the energy storage capacity when executing the declaration data, etc.

[0064] In this embodiment, the energy storage system can generate electric energy by itself through a distributed power source and store it in an energy storage device, or it can obtain and store electric energy through the power grid by being electrically connected to the power grid interface. Among them, the energy storage device obtains revenue by outputting the stored electric energy to the power grid. However, the energy interaction between the energy storage system and the power grid must be reported to the power trading center in advance to ensure the stability of power supply. According to the corresponding rules of the different energy storage systems, the energy storage system can be reported one day or one hour in advance. It is understandable that the revenue obtained by the energy storage system may be different depending on the reporting data generated by the energy storage system. Therefore, the energy storage system needs to obtain the fluctuation data of electricity use in a period of its location and the operating data of the energy storage device, so as to determine the reporting data of the corresponding period and feedback it to the power trading center through the cloud, so as to ensure the maximization of the revenue of the energy storage system.

[0065] In this embodiment, the declared data is both a charge and discharge request fed back to the power trading center and a control instruction for the energy storage device in the subsequent cycle. The control device will control the energy storage device to perform corresponding charge and discharge actions according to the declared data in the corresponding cycle to obtain benefits.

[0066] This embodiment obtains the fluctuation data of electricity usage in a cycle at the location where the energy storage system is located, thereby confirming the usage pattern of the location where the energy storage system is located in a cycle, and judges when the electricity consumption in the location where the energy storage system is located is large, when the electricity consumption is moderate, and when the electricity consumption is low in the cycle, and obtains the electricity price corresponding to each time period in the cycle. Further, by obtaining the operation data of the energy storage device, the amount of electricity stored in the energy storage device and the input and output power are confirmed. By combining the fluctuation data with the operation data, it is confirmed when the energy storage device is charged and when it is discharged, and then the declaration data is confirmed and uploaded to the power trading platform, so that the control device can control the energy storage device to perform corresponding charging and discharging actions in the corresponding time period in the cycle, so as to achieve the effect of improving the economic operation of the energy storage system.

[0067] refer to Figure 2 and Figure 8 In one embodiment of the present invention, the step of obtaining the fluctuation data of power usage in a cycle of the energy storage system and the operation data of the energy storage device specifically includes:

[0068] Step S110: Obtaining the peak period, valley period and stable period of electricity usage in a cycle of the location where the energy storage system belongs;

[0069] Step S120: generating fluctuation data of the energy storage system within a period according to the peak power consumption period, the valley power consumption period and the stable power consumption period;

[0070] Step S130: Obtaining the charging rate, discharging rate and electric energy storage ratio of the energy storage device;

[0071] Step S140: generating operation data of the energy storage device according to the charging rate, the discharging rate and the electric energy storage ratio.

[0072] In this embodiment, the use of electricity in the area where the energy storage system belongs within a cycle can be divided into a peak period, a valley period and a stable period according to the power consumption per unit time. Further, the specific steps of obtaining the peak period, valley period and stable period of electricity use in the area where the energy storage system belongs within a cycle include: obtaining the situation of electricity in the area where the energy storage system belongs within a cycle, and setting the time period when the power consumption per unit time is greater than the first power consumption as the peak period, setting the time period when the power consumption per unit time is less than the second power consumption as the valley period, and setting the time end when the power consumption per unit time is between the first power consumption and the second power consumption as the stable period. Among them, the peak period of electricity consumption is generally in the morning and evening, when most residents start to use a large number of electrical appliances, such as air conditioners, lighting, cooking equipment, etc. During these periods, the power supply is tight and the pressure on the power grid is large, so the electricity price is usually high. The valley period of electricity consumption is generally between late night and early morning, when most people have rested and the power consumption is reduced. During these periods, the power supply is sufficient and the pressure on the power grid is small, so the electricity price is low. The first power setting and the second power setting can be set according to the power consumption in a unit time. For example, the power consumption in a unit time is sorted from high to low. When it is higher than a certain limit of the average power consumption in a unit time, the unit time period is confirmed as a peak power consumption period; when it is lower than a certain limit of the average power consumption in a unit time, the unit time period is confirmed as a valley power consumption period. By confirming the peak power consumption period, valley power consumption period and stable power consumption period in a cycle of the area where the energy storage system is located, the fluctuation data of the area in a cycle is determined, and then the electricity price of each time period in a cycle is confirmed.

[0073] In this embodiment, the energy storage device, as a storage device for electric energy, has the function of obtaining or outputting electric energy and storing electric energy through charging and discharging. Among them, the charging rate, discharge rate and electric energy storage ratio of the energy storage device will affect the declaration of the energy storage system. For example, the fluctuation data shows that the use of electricity in a certain time period belongs to the low electricity consumption period, that is, the electricity price in this time period is at a low price. The control device should control the energy storage device to perform charging action to obtain electric energy at a low price. However, at this time, it is necessary to consider the electric energy storage ratio in the energy storage device. If the electric energy storage ratio is in a saturated state, the charging action cannot be performed. If the electric energy storage ratio has not reached the saturated state, the control device needs to control the energy storage device to charge during the low electricity consumption period by adjusting the charging rate to ensure that the energy storage device can increase the electric energy storage ratio of the squeak as much as possible during the low electricity consumption period. Therefore, the control device needs to obtain the charging rate, discharge rate and electric energy storage ratio of the energy storage device to cooperate with the fluctuation data within a cycle of the energy storage system to achieve economic maximization.

[0074] refer to Figure 3 In one embodiment of the present invention, the step of generating the declaration data of the corresponding period according to the fluctuation data and the operation data specifically includes:

[0075] Step S210: According to the fluctuation data, the time period within the cycle is divided into a peak reporting time period, a trough reporting time period and a stable reporting time period;

[0076] Step S220: According to the operation data, confirm the execution actions of the peak reporting time period, the valley reporting time period and the stable reporting time period.

[0077] In this embodiment, according to the above content, the use of electricity in the area where the energy storage system belongs within a cycle is divided into peak electricity consumption period, valley electricity consumption period and stable electricity consumption period according to the electricity consumption per unit time, and then the time end in the cycle is divided into peak declaration time period, valley declaration time period and stable declaration time period. It can be understood that the energy storage system first needs to confirm the use of electricity in the area where it belongs within a week, so as to confirm whether to choose to obtain electricity from the power grid, output electricity to the power grid, or standby in different time periods in the cycle, so as to obtain economic benefits by using the price difference. Further, after confirming the use of electricity in each time period in the corresponding cycle, it is necessary to further confirm the operation data of the energy storage device. According to the above content, it is proposed that the charging rate, discharge rate and energy storage ratio of the energy storage device will affect the declaration of the energy storage system, and then it is necessary to combine the charging rate, discharge rate and energy storage ratio of the energy storage device with the peak declaration time period, valley declaration time period and stable declaration time period to generate the declaration data of the corresponding cycle, and control the energy storage device to perform corresponding actions in the corresponding cycle. Among them, the peak declaration time period, the valley declaration time period and the stable declaration time also correspond to the electricity prices in that time period, which are high, low and moderate respectively.

[0078] refer to Figure 4 In one embodiment of the present invention, the specific steps of confirming the execution actions of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data include:

[0079] Step S221A: judging whether the peak reporting time period is greater than a first preset time period according to the operation data and the peak reporting time period;

[0080] Step S222A: If the peak reporting time period is greater than a first preset time period, controlling the energy storage device to output electric energy at a first preset discharge rate;

[0081] Step S223A: If the peak reporting time period is less than or equal to the first preset time period, controlling the energy storage device to output electric energy at a second preset discharge rate;

[0082] The second preset discharge rate is greater than the first preset discharge rate.

[0083] It is important to understand that within a cycle of the energy storage system, there are multiple staggered peak periods, valley periods, and stable periods. For different unit time periods of power consumption, the strategies implemented by the control device are also different.

[0084] In this embodiment, the peak declaration time period belongs to the stage of controlling the energy storage device to output electric energy. The control device will judge the time period to confirm whether its duration is greater than the first preset duration. It can be understood that within the time period, the control device needs to control the energy storage device to output as much electric energy as possible to improve economic benefits. However, within the time period, the output electric energy of the energy storage device is related to its discharge rate. Therefore, the control device will confirm whether the time period is greater than the first preset duration. Among them, the first preset duration is the time required for the energy storage device to output its electric energy storage ratio at the maximum discharge rate. When the duration of the peak declaration time period is greater than the first preset duration, it indicates that the duration of the peak declaration time period is longer, and the energy storage device can output electric energy to the power grid at a normal discharge rate. Among them, the normal discharge rate is the first preset discharge rate. When the duration of the peak declaration time period is less than the first preset duration, it indicates that the duration of the peak declaration time period is shorter, and the energy storage device needs to output electric energy to the power grid at the maximum discharge rate. Among them, the maximum discharge rate is the second preset discharge rate. Therefore, the second preset discharge rate is greater than the first preset discharge rate. In addition, there are also some differences in the power consumption per unit time in the peak declaration time period, which causes the electricity price in the peak declaration time period to be in a fluctuating state. Therefore, the control device can further control the discharge rate of the energy storage device so that it is proportional to the power consumption per unit time, thereby improving economic benefits.

[0085] refer to Figure 5 In one embodiment of the present invention, the specific step of confirming the execution action of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data further includes:

[0086] Step S221B: judging whether the valley reporting time period is greater than a second preset time period according to the operation data and the peak reporting time period;

[0087] Step S222B: If the off-peak reporting time period is greater than the second preset time period, controlling the energy storage device to charge electric energy at a first preset charging rate;

[0088] Step S223B: If the off-peak reporting time period is less than or equal to the second preset time period, controlling the energy storage device to charge electric energy at a second preset charging rate;

[0089] The second preset charging rate is greater than the first preset charging rate.

[0090] In this embodiment, the valley declaration time period belongs to the stage of controlling the energy storage device to charge electric energy. The control device will judge the time period to confirm whether its duration is greater than the second preset duration. It can be understood that within the time period, the control device needs to control the energy storage device to charge as much electric energy as possible to reduce the operating cost. As described above, within the time period, the electric energy charged into the energy storage device is related to its charging rate. Therefore, the control device will confirm whether the time period is greater than the second preset duration. Among them, the second preset duration is half of the time required for the energy storage device to charge the electric energy storage remaining proportion at the maximum charging rate. When the duration of the valley declaration time is greater than the second preset duration, it indicates that the duration of the valley declaration time is longer, and the energy storage device can charge electric energy to the energy storage device at a normal charging rate. Among them, the normal charging rate is the first preset charging rate. When the duration of the valley declaration time period is less than the second preset duration, it indicates that the duration of the valley declaration time period is shorter, and the energy storage device needs to charge electric energy to the energy storage device at the maximum charging rate. Among them, the maximum charging rate is the second preset charging rate. Therefore, the second preset charging rate is greater than the first preset charging rate. In addition, there are some differences in the power consumption per unit time in the off-peak declaration time period, which causes the electricity price in the off-peak declaration time period to be in a fluctuating state. Therefore, the control device can further control the charging rate of the energy storage device so that it is inversely proportional to the power consumption per unit time, thereby improving economic benefits.

[0091] refer to Figure 6 , further, if the off-peak reporting time period is greater than the second preset time period, the step of controlling the energy storage device to charge electric energy at the first preset discharge rate is specifically as follows:

[0092] Step S224B: If the off-peak reporting time period is greater than the second preset time period and is less than or equal to twice the second preset time period, controlling the energy storage device to charge electric energy at a first preset charging rate;

[0093] Step S225B: If the off-peak reporting time period is greater than the second preset time period and greater than twice the second preset time period, then the time period in which the off-peak reporting time period is greater than twice the second preset time period is confirmed as a free time period;

[0094] Step S226B: when the free time period is greater than the second preset time length, confirming the peak load benefit in the free time period, selecting a time period in which the peak load benefit is greater than the preset benefit, and controlling the energy storage device to output electric energy at the second preset discharge rate;

[0095] Step S227B: When the free time period is less than or equal to the second preset time period, the peak load benefit in the free time period is confirmed, and the energy storage device is controlled to output electric energy at the second preset discharge rate.

[0096] In this embodiment, if the valley declaration time period is greater than the second preset time length and is less than or equal to twice the second preset time length, it can be confirmed that the time period satisfies the energy storage device to charge the remaining proportion of electric energy storage to a near saturated state. At this time, the control device controls the energy storage device to charge at the first preset charging rate. When the valley declaration time period is greater than the second preset time length and greater than twice the second preset time length, it can be judged that the valley declaration time period is in a longer time period. The control device can control the energy storage device to charge at the first preset charging rate, and when the charging time length reaches twice the second preset time length, the electric energy storage ratio of the energy storage device reaches a saturated state. At this time, there is still some time left in the valley declaration time period, that is, the free time period = valley declaration time period - 2 * second preset time length. When the free time period is greater than the second preset time length, the free time period is further divided into multiple time periods, and the peak load benefit of each time period is confirmed by the control device to obtain the maximum benefit time period. When the benefit is greater than the preset benefit, the time period is declared to output electric energy at the second preset discharge rate; otherwise, the energy storage device is controlled to be in a standby state in the time period. The preset benefit is the peak-valley price difference benefit. When the free time period is less than the second preset duration, the peak load benefit in the free time period is confirmed, and the energy storage device is controlled to output electric energy at the second preset discharge rate.

[0097] refer to Figure 7 In one embodiment of the present invention, the specific step of confirming the execution action of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data further includes:

[0098] Step S221C: confirming, based on the operation data and the fluctuation data, whether the time periods before and after the stable reporting time period belong to the peak reporting time period or the valley reporting time period;

[0099] Step S222C: when the first time period of the stable declaration time period is a valley declaration time period and the second time period is a peak time period, determining whether the stable declaration time period is greater than a third preset time length;

[0100] Step S223C: Under the condition that the stable declaration time period is greater than the third preset time period, confirm the peak-shaving benefit of the stable declaration time period, select a time period in which the peak-shaving benefit is greater than the preset benefit, and control the energy storage device to charge electric energy at a second preset charging rate;

[0101] Step S224C: under the condition that the stable declaration time period is less than or equal to the third preset time period, controlling the energy storage device to charge electric energy at a second preset charging rate;

[0102] Step S225C: when the preceding time period of the stable declaration time period is a peak declaration time period and the succeeding time period is a valley time period, determining whether the stable declaration time period is greater than a third preset time length;

[0103] Step S226C: Under the condition that the stable declaration time period is greater than the third preset time period, confirm the peak-shaving benefit of the stable declaration time period, select a time period in which the peak-shaving benefit is greater than the preset benefit, and control the energy storage device to output electric energy at a second preset charging rate;

[0104] Step S227C: under the condition that the stable declaration time period is less than or equal to the third preset time period, the energy storage device is controlled to output electric energy at a second preset charging rate.

[0105] In this embodiment, the declaration of the stable declaration time period needs to be confirmed according to the operation data and fluctuation data, and the time periods before and after the stable declaration time period belong to the peak declaration time period or the valley declaration time period, so as to confirm the actions required to be performed in the stable declaration time period. If the time period before the stable declaration time period is the valley declaration time period, it can be confirmed that the energy storage device has undergone a charging process, and the time period after the peak declaration time period can be confirmed that the energy storage device needs to undergo a discharge process later. Therefore, the stable time period needs to consider whether the energy storage ratio of the energy storage device meets the subsequent discharge requirements. Further, by judging whether the stable declaration time period is greater than the third preset time length, the actions required to be performed in the stable declaration time period are confirmed. Among them, the third preset time length is the time length required for the energy storage ratio of the energy storage device to be charged at the second charging rate or the time length required for charging at the second discharge rate. When the latter time period is the peak declaration time period, the third preset time length is the time length required for the energy storage ratio of the energy storage device to be charged at the second charging rate. When the stable declaration time period is greater than the third preset time length, the stable declaration time period is divided into multiple time periods, and the peak-shaving benefit of each time period is confirmed by the control device to obtain the maximum benefit time period. When the income is greater than the preset income, the electric energy is charged at the second preset charging rate during the time period. The stable reporting time period can be divided into multiple time periods according to the third preset duration. When the stable reporting time period is less than or equal to the third preset duration, the control device controls the energy storage device to charge the electric energy at the second preset charging rate to ensure that the electric energy storage ratio in the energy storage device is in a relatively saturated state before the peak reporting time period arrives.

[0106] In this embodiment, the time period before the stable declaration time period is the peak declaration time period, and the time period after the stable declaration time period is the valley time period, then it is confirmed that the subsequent stage is the charging stage. Therefore, at this time, the third preset duration is the time required for the energy storage device's electric energy storage ratio to discharge at the second charging rate. When the stable declaration time period is greater than the third preset duration, the stable declaration time period is divided into multiple time periods, and the peak-shaving benefit of each time period is confirmed by the control device to obtain the maximum benefit time period. When the benefit is greater than the preset benefit, the time period is declared to output electric energy at the second preset discharge rate. Among them, the stable declaration time period can be divided into multiple time periods according to the third preset duration. When the stable declaration time period is less than or equal to the third preset duration, the control device controls the energy storage device to output electric energy at the second preset discharge rate to ensure that before the valley declaration time period arrives, the electric energy storage ratio in the energy storage device is in a relatively low state.

[0107] The present invention also proposes a control device, the control device comprising: a memory, a processor, and a control program for an energy storage system stored in the memory and running on the processor, the control program being configured to implement the steps of the control method for the energy storage system as described in any one of the above. It is worth noting that since the control device of the present invention is based on the above-mentioned control method for the energy storage system, the embodiments of the control device of the present invention include all technical solutions of all embodiments of the above-mentioned control method for the energy storage system, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0108] The present invention also proposes an energy storage system, which includes the control device and energy storage device, a grid interface and a cloud as described above. It is worth noting that since the energy storage system of the present invention is based on the above-mentioned control device, the embodiments of the energy storage system of the present invention include all technical solutions of all embodiments of the above-mentioned control device, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0109] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A control method for an energy storage system, characterized in that: The energy storage system includes an energy storage device, a control device, a power grid interface and a cloud, the energy storage device is electrically connected to the power grid interface and the control device respectively, the control device is communicatively connected to the cloud, and the method includes: Obtaining fluctuation data of power usage in a cycle at the location of the energy storage system and operation data of the energy storage device; Generate declaration data of a corresponding period according to the fluctuation data and the operation data; The energy storage device is controlled to perform charging and discharging actions within a corresponding period according to the reported data.

2. The method according to claim 1, characterized in that The step of obtaining the fluctuation data of power usage in a cycle of the energy storage system and the operation data of the energy storage device specifically includes: Obtain the peak period, the low period and the stable period of electricity usage in a cycle of the location where the energy storage system belongs; Generate fluctuation data within a cycle of the energy storage system according to the peak power consumption period, the valley power consumption period and the stable power consumption period; Obtaining the charging rate, discharging rate and electric energy storage ratio of the energy storage device; The operation data of the energy storage device is generated according to the charging rate, the discharging rate and the electric energy storage ratio.

3. The method according to claim 2, characterized in that The specific steps of obtaining the peak period, valley period and stable period of electricity usage in a cycle of the energy storage system include: The power situation of the location where the energy storage system is located within a cycle is obtained, and the time period when the power consumption per unit time is greater than the first power consumption is set as the peak power consumption period, the time period when the power consumption per unit time is less than the second power consumption is set as the valley power consumption period, and the time period when the power consumption per unit time is between the first power consumption and the second power consumption is set as the stable power consumption period.

4. The method according to claim 3, characterized in that The step of generating the declaration data of the corresponding period according to the fluctuation data and the operation data specifically includes: According to the fluctuation data, the time period within the cycle is divided into a peak reporting time period, a trough reporting time period and a stable reporting time period; According to the operation data, the execution actions of the peak reporting time period, the valley reporting time period and the stable reporting time period are confirmed.

5. The method according to claim 4, characterized in that The specific steps of confirming the execution actions of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data include: According to the operation data and the peak reporting time period, determining whether the peak reporting time period is greater than a first preset time period; If the peak reporting time period is greater than a first preset time period, controlling the energy storage device to output electric energy at a first preset discharge rate; If the peak reporting time period is less than or equal to the first preset time period, controlling the energy storage device to output electric energy at a second preset discharge rate; The second preset discharge rate is greater than the first preset discharge rate.

6. The method according to claim 4, characterized in that The specific step of confirming the execution of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data further includes: According to the operation data and the peak reporting time period, determining whether the valley reporting time period is greater than a second preset time period; If the off-peak reporting time period is greater than the second preset time period, controlling the energy storage device to charge electric energy at a first preset charging rate; If the off-peak reporting time period is less than or equal to the second preset time period, controlling the energy storage device to charge electric energy at a second preset charging rate; The second preset charging rate is greater than the first preset charging rate.

7. The method according to claim 6, characterized in that If the off-peak reporting time period is greater than the second preset time period, the step of controlling the energy storage device to charge electric energy at the first preset discharge rate is specifically as follows: If the off-peak reporting time period is greater than the second preset time period and is less than or equal to twice the second preset time period, controlling the energy storage device to charge electric energy at a first preset charging rate; If the off-peak reporting time period is greater than the second preset time period and greater than twice the second preset time period, the time period in which the off-peak reporting time period is greater than twice the second preset time period is confirmed as the free time period; When the free time period is greater than the second preset time length, the peak load benefit in the free time period is confirmed, and a time period in which the peak load benefit is greater than the preset benefit is selected, and the energy storage device is controlled to output electric energy at the second preset discharge rate; When the free time period is less than or equal to the second preset time length, the peak load benefit in the free time period is confirmed, and the energy storage device is controlled to output electric energy at a second preset discharge rate.

8. The method according to claim 4, characterized in that The specific step of confirming the execution of the peak reporting time period, the valley reporting time period and the stable reporting time period according to the operation data further includes: According to the operation data and the fluctuation data, confirm that the time periods before and after the stable reporting time period belong to the peak reporting time period or the valley reporting time period; When the first time period of the stable declaration time period is a valley declaration time period and the second time period is a peak time period, determining whether the stable declaration time period is greater than a third preset time length; Under the condition that the stable declaration time period is greater than the third preset time period, confirming the peak-shaving benefit of the stable declaration time period, and selecting a time period in which the peak-shaving benefit is greater than the preset benefit, and controlling the energy storage device to charge electric energy at a second preset charging rate; Under the condition that the stable declaration time period is less than or equal to the third preset time period, controlling the energy storage device to charge electric energy at a second preset charging rate; When the first time period of the stable declaration time period is a peak declaration time period and the second time period is a valley time period, determining whether the stable declaration time period is greater than a third preset time length; Under the condition that the stable declaration time period is greater than the third preset time length, confirming the peak-shaving benefit of the stable declaration time period, and selecting a time period in which the peak-shaving benefit is greater than the preset benefit, and controlling the energy storage device to output electric energy at a second preset charging rate; Under the condition that the stable declaration time period is less than or equal to the third preset time period, the energy storage device is controlled to output electric energy at a second preset charging rate.

9. A control device, characterized in that: The control device includes: a memory, a processor, and a control program of the energy storage system stored in the memory and running on the processor, wherein the control program is configured to implement the steps of the control method of the energy storage system as described in any one of claims 1 to 8 above.

10. An energy storage system, characterized in that: The energy storage system includes the control device and energy storage device as claimed in claim 9, a power grid interface and a cloud.

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