CN115021301B

CN115021301B - Energy storage system charge and discharge control method, device, equipment and storage medium

Info

Publication number: CN115021301B
Application number: CN202210944376.2A
Authority: CN
Inventors: 卓清锋
Original assignee: Shenzhen Guorui Xiechuang Energy Storage Technology Co ltd
Current assignee: Shenzhen Guorui Xiechuang Energy Storage Technology Co ltd
Priority date: 2022-08-08
Filing date: 2022-08-08
Publication date: 2022-12-23
Anticipated expiration: 2042-08-08
Also published as: CN115021301A

Abstract

The invention relates to the technical field of energy storage systems, in particular to a method, a device, a computing device and a computer readable storage medium for controlling charging and discharging of an energy storage system, wherein the method comprises the following steps: acquiring the actual output power of the inverter under the condition that the power grid is connected into the charging and discharging unit or under the condition that the power of the charging and discharging unit connected into the power grid is changed; obtaining rated power of an inverter; determining the load rate of the inverter according to the rated power and the actual output power of the inverter; when the load rate is judged to be smaller than a first preset threshold value, controlling at least part of the first inversion modules and the second inversion modules to enter a dormant state so as to enable the load rate to be larger than or equal to the first preset threshold value; and when the load rate is judged to be greater than or equal to the first preset threshold value, controlling the inverter to perform charging and discharging work at the load rate. Through the mode, the inverter can work in a high-efficiency interval, the power consumption is reduced, and the overall benefit of an energy storage system is improved.

Description

Energy storage system charge and discharge control method, device, equipment and storage medium

Technical Field

The invention relates to the technical field of energy storage systems, in particular to a charge and discharge control method and device of an energy storage system, computing equipment and a computer readable storage medium.

Background

The efficiency of an energy storage system refers to the ratio of output power to input power of a device (e.g., inverter, transformer, etc.), which is affected by many factors.

The efficiency of an inverter in the conventional energy storage system is influenced by factors such as load rate and the like, so that the efficiency is unstable, the power consumption of the system is increased, and the overall benefit of the energy storage system is influenced.

Disclosure of Invention

In view of the above problems, the present invention provides a method, an apparatus, a computing device, and a computer-readable storage medium for controlling charging and discharging of an energy storage system, which can enable an inverter to operate in a high efficiency region, reduce power consumption, and improve overall benefits of the energy storage system.

According to one aspect of the invention, an energy storage system charge and discharge control method is provided, the energy storage system comprises an inverter and a power grid, the inverter comprises a plurality of first inversion modules and a plurality of second inversion modules, the efficiency of the first inversion modules is greater than that of the second inversion modules, and the first inversion modules and the second inversion modules both have an on state and a sleep state; the method comprises the following steps: acquiring the actual output power of the inverter under the condition that the power grid is connected into the charging and discharging unit or under the condition that the power of the charging and discharging unit connected into the power grid is changed; acquiring rated power of an inverter, wherein the rated power is the sum of first rated power of a first inverter module in an on state and second rated power of a second inverter module in the on state; determining the load rate of the inverter according to the rated power and the actual output power of the inverter; when the load rate is judged to be smaller than a first preset threshold value, controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a dormant state so as to enable the load rate to be larger than or equal to the first preset threshold value; and when the load rate is judged to be greater than or equal to the first preset threshold value, controlling the inverter to perform charging and discharging work at the load rate.

In the charge and discharge control method for the energy storage system, provided by the embodiment of the invention, the inverter is set to comprise a plurality of first inversion modules and a plurality of second inversion modules, the efficiency of the first inversion modules is higher than that of the second inversion modules, so that the rated power of the inverter can be adjusted by controlling the number of the first inversion modules and the number of the second inversion modules in the open state, and further, the adjustment of the load rate of the inverter is realized by judging the size relationship between the load rate and a first preset threshold value, so that the load rate of the inverter for charge and discharge work is in a higher efficiency interval, the problems of low efficiency and high system power consumption of the inverter under light load are effectively solved, and the overall benefit of the energy storage system is improved.

In an optional manner, when the load rate is determined to be less than the first preset threshold, controlling at least part of the plurality of first inverter modules and the plurality of second inverter modules to enter the sleep state, so that the load rate is greater than or equal to the first preset threshold, including: when the load rate is judged to be smaller than a first preset threshold value, controlling a first inversion module or a second inversion module to enter a dormant state, wherein the second inversion module is preferentially controlled to enter the dormant state; and repeatedly acquiring the rated power of the inverter until the load rate is judged to be greater than or equal to the first preset threshold value. The method comprises the steps of controlling a first inversion module or a second inversion module to enter a dormant state one by one to enable the rated power of an inverter to be gradually reduced, further gradually increasing the load rate, obtaining the rated power of the inverter once when controlling the first inversion module or the second inversion module to enter the dormant state, judging whether the adjusted load rate is smaller than a first preset threshold value or not based on the rated power and actual output power, ending circulation until the load rate is larger than or equal to the first preset threshold value, controlling the inverter to carry out charging and discharging work at the load rate, and ensuring that the inverter is in a high-efficiency interval. Because the efficiency of the first inversion module is higher than that of the second inversion module under the condition of the same load rate, more first inversion modules can work by preferentially controlling the second inversion module to enter a dormant state, so that the inverter has higher working efficiency and the power consumption of the system is fully reduced.

In an optional manner, when the load rate is determined to be less than the first preset threshold, controlling at least part of the plurality of first inverter modules and the plurality of second inverter modules to enter the sleep state, so that the load rate is greater than or equal to the first preset threshold, including: when the load rate is judged to be smaller than a first preset threshold value, determining a corresponding first required rated power when the load rate is larger than or equal to the first preset threshold value according to the actual output power; and controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a dormant state according to the first required rated power so that the rated power of the inverter is equal to the first required rated power, wherein the second inversion modules are preferentially controlled to enter the dormant state. Through the mode, compared with a method for controlling the first inversion module or the second inversion module to enter the dormant state one by one, the efficiency of adjusting the load rate of the inverter can be improved, the load rate can be quickly adjusted to a required size, and the inverter can further work in a high-efficiency interval more quickly.

In an optional manner, before obtaining the rated power of the inverter, the method further comprises: controlling one or more first inversion modules to be in an on state, and controlling the second inversion modules and the rest number of first inversion modules to be in a dormant state; when the load factor is judged to be greater than or equal to a first preset threshold value, the inverter is controlled to carry out charging and discharging work at the load factor, and the method comprises the following steps: when the load rate is judged to be greater than or equal to a first preset threshold and greater than a second preset threshold, controlling at least part of the first inversion module and the second inversion module in the dormant state to enter an open state, so that the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold; and when the load rate is judged to be greater than or equal to the first preset threshold and less than or equal to the second preset threshold, controlling the inverter to perform charging and discharging work at the load rate. Through the scheme, the load rate of the inverter can be controlled between the first preset threshold and the second preset threshold, so that the inverter can be ensured to work in a high-efficiency interval better, the power consumption is further reduced, and the benefit is improved.

In an optional manner, when it is determined that the load rate is greater than or equal to the first preset threshold and greater than the second preset threshold, controlling at least a part of the first inverter module and the second inverter module in the sleep state to enter an on state, so that the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, including: when the load rate is judged to be greater than or equal to a first preset threshold value and greater than a second preset threshold value, controlling a first inversion module in a dormant state or a second inversion module in the dormant state to enter an open state, wherein the first inversion module is preferentially controlled to enter the open state; and repeatedly acquiring the rated power of the inverter until the load rate is judged to be greater than or equal to the first preset threshold and less than or equal to the second preset threshold. The method comprises the steps of controlling first inversion modules or second inversion modules which are in a dormant state to enter an open state one by one to enable the rated power of an inverter to be increased gradually, further reducing the load rate gradually, obtaining the rated power of the inverter once when controlling one first inversion module or second inversion module to enter the dormant state, judging whether the adjusted load rate is larger than a second preset threshold value or not based on the rated power and actual output power, ending circulation after the load rate is smaller than or equal to the second preset threshold value, controlling the inverter to carry out charging and discharging work at the load rate, ensuring that the load rate of the inverter during the charging and discharging work is between the first preset threshold value and the second preset threshold value, and ensuring the working efficiency of the inverter. Because the efficiency of the first inversion module is higher than that of the second inversion module under the condition of the same load rate, more first inversion modules can work by preferentially controlling the first inversion modules to enter an open state, so that the inverter has higher working efficiency, and the power consumption of the system is fully reduced.

In an optional manner, when it is determined that the load rate is greater than or equal to the first preset threshold and greater than the second preset threshold, controlling at least a part of the first inverter module and the second inverter module in the sleep state to enter an on state, so that the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, including: when the load rate is judged to be greater than or equal to a first preset threshold and greater than a second preset threshold, determining a corresponding second required rated power when the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold according to the actual output power; and controlling at least part of the first inversion module and the second inversion module in the dormant state to enter an on state according to the second required rated power so as to enable the rated power of the inverter to be equal to the second required rated power, wherein the first inversion module is preferentially controlled to enter the on state. Through the mode, compared with a method for controlling the first inversion module or the second inversion module to enter the opening state one by one, the method can improve the efficiency of adjusting the load rate of the inverter, so that the load rate can be quickly adjusted to a required size, and the inverter can further work in a high-efficiency interval more quickly.

In an optional manner, the method further comprises: judging whether the sum of the number of the first inversion modules and the number of the second inversion modules in the starting state is equal to 1 or not; and if so, controlling at least one first inversion module and/or at least one second inversion module to enter an opening state. In consideration of the fact that only one first inverter module or one second inverter module is finally adjusted to perform charging and discharging operations, in the practical application process, when the first inverter module or the second inverter module performing the charging and discharging operations fails, the circuit can be directly broken, and the continuous operation cannot be performed. Therefore, after the number of the inversion modules in the working state is adjusted, whether the number of the inversion modules in the working state is 1 or not is judged, and at least one inversion module is controlled to enter the working state when the number is 1, so that at least two inversion modules are ensured to carry out charging and discharging work, and when a certain inversion module fails, the charging and discharging work can be continued through the other inversion module, and the stability of the charging and discharging work of the energy storage system is ensured.

According to another aspect of the present invention, there is provided a charge and discharge control apparatus for an energy storage system, the energy storage system includes an inverter and a power grid, the inverter includes a plurality of first inverter modules and a plurality of second inverter modules, the efficiency of the first inverter modules is greater than that of the second inverter modules, and the first inverter modules and the second inverter modules both have an on state and a sleep state; the device comprises: the first acquisition unit is used for acquiring the actual output power of the inverter under the condition that a power grid is connected to the charging and discharging unit or under the condition that the power of the charging and discharging unit connected to the power grid is changed; the second obtaining unit is used for obtaining the rated power of the inverter, and the rated power is the sum of the first rated power of the first inverter module in the starting state and the second rated power of the second inverter module in the starting state; the determining unit is used for determining the load factor of the inverter according to the rated power and the actual output power of the inverter; the first control unit is used for controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a dormant state when the load rate is judged to be smaller than a first preset threshold value, so that the load rate is larger than or equal to the first preset threshold value; and the second control unit is used for controlling the inverter to carry out charging and discharging work at the load rate when the load rate is judged to be greater than or equal to the first preset threshold value.

In the charge and discharge control device for the energy storage system provided by the embodiment of the invention, the inverter is arranged to comprise a plurality of first inversion modules and a plurality of second inversion modules, the efficiency of the first inversion modules is higher than that of the second inversion modules, so that the rated power of the inverter can be adjusted by controlling the number of the first inversion modules and the number of the second inversion modules in the open state through the first control unit 240, the adjustment of the load rate of the inverter is further realized, the load rate of the inverter for performing charge and discharge work is in a higher efficiency interval, the problems of low efficiency and high system power consumption of the inverter under light load are effectively solved, and the overall benefit of the energy storage system is improved.

According to another aspect of the invention, there is provided a computing device comprising: the processor, the memory and the communication interface complete mutual communication through the communication bus; the memory is used for storing at least one executable instruction, and the executable instruction causes the processor to execute the operation of the energy storage system charging and discharging control method.

According to another aspect of the present invention, a computer-readable storage medium is provided, where at least one executable instruction is stored in the storage medium, and when the executable instruction is executed on a computing device, the computing device is caused to perform the operations of the energy storage system charging and discharging control method according to any one of the above.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic structural diagram of a charge-discharge loop of an energy storage system according to an embodiment of the present invention;

fig. 2 is a graph of the relationship between the efficiency and the load factor of two conventional series of ordinary energy storage inverters provided by the embodiment of the present invention;

fig. 3 is a graph illustrating the relationship between the efficiency and the load factor of an energy storage inverter using a novel switching device according to an embodiment of the present invention;

fig. 4 is a flowchart of a charge and discharge control method for an energy storage system according to an embodiment of the present invention;

FIG. 5 is a flow diagram of sub-steps of step 150 of FIG. 4;

FIG. 6 is a flowchart illustrating another substep of step 150 of FIG. 4;

fig. 7 is a flowchart of a charge/discharge control method for an energy storage system according to another embodiment of the present invention;

FIG. 8 is a flow chart of sub-steps of step 161 of FIG. 7;

FIG. 9 is a flowchart illustrating another substep of step 161 of FIG. 7;

fig. 10 is a flowchart illustrating further steps of a method for controlling charging and discharging of an energy storage system according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a charge and discharge control device of an energy storage system according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a computing device according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein.

As shown in fig. 1, a charging and discharging loop of the energy storage system generally includes four parts, i.e., an energy storage battery 1 (e.g., a lithium battery), an inverter 2, a step-up transformer 3, and a power grid 4, and is additionally provided with protective devices such as a circuit breaker and a connecting cable to form a complete energy storage system. The efficiency of charging and discharging can measure the energy consumption on the power loop, which directly affects the yield of the energy storage system.

As shown in fig. 2, the graph shows the relationship curve between the efficiency and the load factor of two conventional series of ordinary energy storage inverters, where the load factor refers to the ratio of the actual output power of the inverter to the rated power, and it can be known from the graph that the efficiency of the inverter is high when the load factor is in the interval of 40% -60%, the efficiency is low when the load factor is greater than 60%, and the efficiency is very low when the load factor is less than 30%.

By adopting the novel switching device such as silicon carbide (SIC) and gallium nitride (GaN), the efficiency of the energy storage inverter can be improved, specifically as shown in fig. 3, compared with the common inverter shown in fig. 2, after the novel switching device such as silicon carbide (SIC) and gallium nitride (GaN) is applied to the common energy storage inverter, the efficiency of the inverter in the interval of 0-30% load rate is obviously improved, and the efficiency in the interval of 40-60% load rate is further improved.

Based on this, the inverter is configured to include a plurality of first inversion modules and a plurality of second inversion modules, wherein the switching device of the first inversion module can adopt a novel switching device such as silicon carbide (SIC), gallium nitride (GaN), and the like, and the second inversion module adopts a common inversion module, so that the efficiency of the first inversion module is higher than that of the second inversion module, and the operating state (open state or dormant state) of different inversion modules in the inverter is adjusted under the condition that different inverters are at lower load rates, so that the inverter is at the load rate corresponding to higher efficiency, thereby ensuring that the inverter operates in a high-efficiency interval, further reducing the power consumption of the energy storage system, and improving the overall yield of the energy storage system.

In the charge and discharge control method for the energy storage system, the energy storage system comprises an inverter and a power grid, the inverter comprises a plurality of first inversion modules and a plurality of second inversion modules, the efficiency of the first inversion modules is higher than that of the second inversion modules, and the first inversion modules and the second inversion modules are both in an open state and a dormant state. Referring to fig. 4 in particular, a flow of a charge and discharge control method for an energy storage system according to an embodiment of the present invention is shown in the drawing. The method may be performed by a computing device, such as a computer, controller, server, or the like. As shown in the figure, the method comprises:

step 110: and acquiring the actual output power of the inverter under the condition that the power grid is connected into the charging and discharging unit or under the condition that the power of the charging and discharging unit connected into the power grid is changed.

In this step, the charging and discharging unit connected to the power grid may be a power consumption unit that receives power from the energy storage system, or may be a charging unit that inputs power to the energy storage system. After the power grid is connected to the charging and discharging unit, power transmission is started between the power grid and the charging and discharging unit, and as shown in fig. 1, the actual output power of the inverter can be obtained by detecting the magnitude of the power output by the inverter to the step-up transformer (when the energy storage system is discharging) or the magnitude of the power output by the inverter to the energy storage battery (when the energy storage system is charging). When the power of the charging and discharging unit connected to the power grid changes, the actual output power of the inverter can be obtained through the mode. For convenience of explanation, the actual output power of the inverter obtained is represented by Pout.

Step 120: and acquiring the rated power of the inverter, wherein the rated power is the sum of the first rated power of the first inverter module in the starting state and the second rated power of the second inverter module in the starting state.

Specifically, in the initial state, all the first inverter modules and all the second inverter modules may be in an on state, or at least some of the first inverter modules and the second inverter modules may be in an on state, and the rest of the first inverter modules and the second inverter modules may be in a sleep state.

In order to take into account the cost behind the novel switching device of first contravariant module adoption and the working property of inverter, the preferred 3 of quantity ratio of first contravariant module and second contravariant module: 7. for example, the number of the first inverter modules may be 3, and the number of the second inverter modules may be 7, where when the load ratio of the first inverter module is equal to the load ratio of the second inverter module, the efficiency η 1 of the first inverter module is greater than the efficiency η 2 of the second inverter module. If the number of the first inverter modules is m, the first rated power of the first inverter module is Pe1, the number of the second inverter modules is n, the second rated power of the second inverter module is Pe2, and all the inverter modules are in an on state in an initial state, the rated power Pe = mPe1+ nPe2 of the inverter obtained in step 110, where Pe1 may be equal to Pe2, or may be different from Pe2, which is not limited herein.

Step 130: and determining the load rate of the inverter according to the rated power and the actual output power of the inverter.

Specifically, the load ratio η x = Pout/Pe of the inverter.

Step 140: judging whether the load rate is smaller than a first preset threshold value or not;

if the determination in step 140 is yes, the following steps are performed:

step 150: and controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a dormant state so that the load rate is greater than or equal to a first preset threshold value.

In this step, at least part of the plurality of first inverter modules and the plurality of second inverter modules is controlled to enter a sleep state, so that the rated power Pe of the inverter is reduced, and based on η x = Pout/Pe, the load factor η x is correspondingly increased, and further the load factor satisfies a condition that the load factor is greater than or equal to a first preset threshold value.

Specifically, the first preset threshold may be set to 30% according to the load rate and efficiency relationship curve of the general inverter module (i.e., the second inverter module) shown in fig. 2 and the load rate and efficiency relationship curve of the high-efficiency inverter module (i.e., the first inverter module) shown in fig. 3. In order to operate the inverter in the higher efficiency region, the first preset threshold may be set to 40%.

If the determination in step 140 is no, the following steps are performed:

step 160: and controlling the inverter to perform charging and discharging operations at the load factor.

In this step, when the load factor is greater than or equal to the first preset threshold, it indicates that the inverter is in a higher efficiency interval, so that the inverter is controlled to perform charging and discharging operations at the load factor, and the power consumption of the system can be effectively reduced.

For the adjusting method of the first inverter module and the second inverter module, the present application further provides an implementation manner, and specifically refers to fig. 5, which illustrates a sub-step flow of step 150 according to an embodiment of the present invention. As shown in the figure, the above step 150 includes the following steps:

step 151: and controlling a first inversion module or a second inversion module to enter a dormant state, wherein the second inversion module is preferentially controlled to enter the dormant state.

In this step, preferentially controlling the second inverter modules to enter the sleep state means that the second inverter modules are controlled to enter the sleep state as long as the second inverter modules in the on state exist, and the first inverter modules are controlled to enter the sleep state only when all the second inverter modules are in the sleep state.

Step 153: the above step 120 is repeatedly executed until the determination in step 140 is no.

In steps 151 to 153, the first inverter module or the second inverter module is controlled to enter the sleep state one by one, so that the rated power of the inverter is gradually reduced, and then the load rate is gradually increased, the rated power of the inverter is obtained once when one first inverter module or one second inverter module is controlled to enter the sleep state, whether the adjusted load rate is smaller than a first preset threshold value or not is judged based on the rated power and the actual output power, and the cycle is ended until the load rate is larger than or equal to the first preset threshold value, and the inverter is controlled to perform charging and discharging work at the load rate, so that the inverter is ensured to be in a high-efficiency interval. Because the efficiency of the first inversion module is higher than that of the second inversion module under the condition of the same load rate, more first inversion modules can work by preferentially controlling the second inversion module to enter a dormant state, so that the inverter has higher working efficiency and the power consumption of the system is fully reduced.

For the adjusting method of the first inverter module and the second inverter module, the present application further provides an implementation manner, and refer to fig. 6 specifically, which illustrates a sub-step flow of the step 150 according to another embodiment of the present invention. As shown in the figure, step 150 comprises the steps of:

step 152: and determining a corresponding first required rated power when the load rate is greater than or equal to a first preset threshold value according to the actual output power.

Step 154: and controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a sleep state according to the first required rated power so that the rated power of the inverter is equal to the first required rated power, wherein the second inversion modules are preferentially controlled to enter the sleep state.

In step 152, the first rated power Pe1 of the first inverter module and the second rated power Pe2 of the second inverter module may be input in advance, and the computing device determines the rated power Pe = m1Pe1+ n1Pe2 of the current inverter according to the number m1 of the first inverter modules currently in the on state and the number n1 of the second inverter modules currently in the on state.

Through calculation, if the load factor can meet the requirement that the load factor is greater than or equal to the first preset threshold value only by adjusting the number of the second inverter modules in the on state to n2, the first required rated power Pe '= m1Pe1+ n2Pe2, and then in step 153, the (n 1-n 2) second inverter modules are controlled to enter the sleep state, so that the rated power Pe of the inverter is equal to the first required rated power Pe'. If all the second inverter modules need to be adjusted to the sleep state and the number of the first inverter modules in the on state needs to be adjusted to m2 to enable the load factor to meet the requirement that the load factor is greater than or equal to the first preset threshold, the first required rated power Pe '= m2Pe1, and accordingly, in step 153, all the second inverter modules are controlled to enter the sleep state, and (m 1-m 2) first inverter modules are controlled to be in the sleep state to enable the rated power Pe of the inverter to be equal to the first required rated power Pe'.

Through the mode, compared with a method for controlling the first inversion module or the second inversion module to enter the dormant state one by one, the efficiency of adjusting the load rate of the inverter can be improved, the load rate can be quickly adjusted to a required size, and the inverter can further work in a high-efficiency interval more quickly.

Referring to fig. 7, a flow of a charge and discharge control method of an energy storage system according to another embodiment of the present invention is shown. As shown in the figure, before step 110, the method further comprises the steps of:

step 101: and controlling one or more first inversion modules to be in an on state, and controlling the second inversion module and the rest number of first inversion modules to be in a dormant state.

In this step, the number of the first inverter modules that are in the on state under the initial condition may be set on the computing device in advance, or the number of the first inverter modules that are in the on state after the previous charging and discharging operation is finished may be directly set as the number of the first inverter modules that are in the on state when the energy storage system does not perform the charging and discharging operation.

The above step 160 includes the following steps:

step 161: and judging whether the load rate is greater than a second preset threshold value.

Referring again to fig. 2 and 3, as shown in the figure, the efficiency of the inverter is reduced after the load factor of the inverter is greater than 60%, and the efficiency is reduced after 80%. Therefore, the second preset threshold may be set to 80% to ensure that the inverter can operate in a higher efficiency range. In order to further improve the efficiency of the inverter, the second preset threshold may be set to 60%, where the second preset threshold is only used for illustration and is not limited to a specific value.

If the determination at step 161 is yes, then the following steps are performed:

step 162: at least part of the first inversion module and the second inversion module in the dormant state is controlled to enter an open state, so that the load rate is greater than or equal to a first preset threshold and less than or equal to a second preset threshold.

If the determination in step 161 is no, then the following steps are performed:

step 163: and controlling the inverter to perform charging and discharging operations at the load factor.

Through the scheme, the load rate of the inverter can be controlled between the first preset threshold and the second preset threshold, so that the inverter can be ensured to work in a high-efficiency interval better, the power consumption is further reduced, and the benefit is improved.

Referring to fig. 8, a flow of sub-steps of the above step 162 provided by the embodiment of the present invention is shown. As shown in the figure, step 162 includes the steps of:

step 1621: and controlling a first inversion module in a dormant state or a second inversion module in the dormant state to enter an open state, wherein the first inversion module is preferentially controlled to enter the open state.

Step 1623: the above step 120 is repeatedly executed until the determination in step 160 is no.

In steps 1621 to 1623, the first inverter module or the second inverter module in the sleep state is controlled to enter the on state one by one, so that the rated power of the inverter is gradually increased, and then the load rate is gradually decreased, the rated power of the inverter is obtained once when one first inverter module or one second inverter module is controlled to enter the sleep state, whether the adjusted load rate is greater than a second preset threshold value or not is judged based on the rated power and the actual output power, and the cycle is ended until the load rate is less than or equal to the second preset threshold value, the inverter is controlled to perform charging and discharging operations at the load rate, the load rate when the inverter performs the charging and discharging operations is ensured to be between the first preset threshold value and the second preset threshold value, and the working efficiency of the inverter is ensured. Because the efficiency of the first inversion module is higher than that of the second inversion module under the condition of the same load rate, more first inversion modules can work by preferentially controlling the first inversion modules to enter the open state, so that the inverter has higher working efficiency and the power consumption of the system is fully reduced.

Referring to fig. 9, a flow of sub-steps of the above step 162 according to another embodiment of the present invention is shown. As shown in the figure, step 162 includes the steps of:

step 1622: and determining a corresponding second required rated power when the load rate is greater than or equal to a first preset threshold and less than or equal to a second preset threshold according to the actual output power.

Step 1624: and controlling at least part of the first inversion module and the second inversion module in the dormant state to enter an on state according to the second required rated power so as to enable the rated power of the inverter to be equal to the second required rated power, wherein the first inversion module is preferentially controlled to enter the on state.

In step 1622, the first rated power Pe1 of the first inverter module and the second rated power Pe2 of the second inverter module may be input in advance on the computer, and the computing device determines the rated power Pe = m3Pe1+ n3Pe2 of the current inverter according to the number m3 of the first inverter modules currently in the on state and the number n3 of the second inverter modules currently in the on state.

Through calculation, if the load factor can meet the requirement that the load factor is greater than or equal to the first preset threshold and less than or equal to the second preset threshold by only increasing the number of the first inverter modules in the on state to m4, the second required rated power Pe "= m4Pe1+ n3Pe2, and then in step 153, (m 4-m 3) first inverter modules are controlled to enter the on state, so that the rated power Pe of the inverter is equal to the second required rated power Pe". If the total number of the first inverter modules is m, all the first inverter modules need to be adjusted to be in an on state, and the number of the second inverter modules in the on state needs to be increased to n5 at the same time, so that the load factor can meet the requirement that the load factor is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, then the second required rated power Pe ″ = mPe1+ n5Pe2, and accordingly, in step 153, all the first inverter modules are controlled to enter the on state, and (n 5-n 3) second inverter modules are controlled to enter the on state, so that the rated power Pe of the inverter is equal to the first required rated power Pe'.

Through the mode, compared with a method for controlling the first inversion module or the second inversion module to enter the opening state one by one, the method can improve the efficiency of adjusting the load rate of the inverter, enable the load rate to be rapidly adjusted to a required size, and further enable the inverter to work in a high-efficiency interval more rapidly.

Referring to fig. 10, a further flow of the energy storage system charge and discharge control method according to the embodiment of the present invention is shown. As shown in the figure, the method further comprises the steps of:

step 170: and judging whether the sum of the number of the first inversion modules and the number of the second inversion modules in the starting state is equal to 1.

If the judgment in the step 170 is yes, the following steps are carried out:

step 180: and controlling at least one first inversion module and/or at least one second inversion module to enter an opening state.

In step 150, if only one first inverter module or one second inverter module is finally adjusted to perform charging and discharging operations, in the actual application process, when the first inverter module or the second inverter module performing charging and discharging operations fails, the circuit may be directly disconnected and cannot continue to operate. Therefore, after the number of the inversion modules in the working state is adjusted, whether the number of the inversion modules in the working state is 1 or not is judged, and at least one inversion module is controlled to enter the working state when the number is 1, so that at least two inversion modules are ensured to carry out charging and discharging work, and when a certain inversion module fails, the charging and discharging work can be continued through the other inversion module, and the stability of the charging and discharging work of the energy storage system is ensured.

For the step 180, at least one first inverter module may be preferentially controlled to enter the operating state, so that the inverter has higher efficiency.

According to another aspect of the embodiments of the present invention, there is also provided a charge and discharge control apparatus for an energy storage system, where the energy storage system includes an inverter and a power grid, the inverter includes a plurality of first inverter modules and a plurality of second inverter modules, the efficiency of the first inverter modules is greater than that of the second inverter modules, and each of the first inverter modules and the second inverter modules has an on state and a sleep state. Referring to fig. 11, a schematic structural diagram of a charge and discharge control device of an energy storage system according to an embodiment of the present invention is shown. As shown in the drawing, the energy storage system charge and discharge control apparatus 200 includes: a first acquisition unit 210, a second acquisition unit 220, a determination unit 230, a first control unit 240, a second control unit 250. The first obtaining unit 210 is configured to obtain actual output power of the inverter under a condition that a power grid is connected to the charging and discharging unit or under a condition that power of the charging and discharging unit connected to the power grid is changed. The second obtaining unit 220 is configured to obtain a rated power of the inverter, where the rated power is a sum of a first rated power of the first inverter module in an on state and a second rated power of the second inverter module in the on state. The determining unit 230 is configured to determine a load factor of the inverter according to the rated power and the actual output power of the inverter. The first control unit 240 is configured to control at least a part of the plurality of first inverter modules and the plurality of second inverter modules to enter a sleep state when determining that the load rate is less than a first preset threshold, so that the load rate is greater than or equal to the first preset threshold. The second control unit 250 is configured to control the inverter to perform charging and discharging operations at the load rate when the load rate is greater than or equal to the first preset threshold.

In the energy storage system charge and discharge control device 200 provided in the embodiment of the present invention, the inverter is configured to include a plurality of first inverter modules and a plurality of second inverter modules, and the efficiency of the first inverter modules is greater than the efficiency of the second inverter modules, so that the rated power of the inverter can be adjusted by controlling the number of the first inverter modules and the number of the second inverter modules in the on state through the first control unit 240, thereby adjusting the load factor of the inverter, and making the load factor of the inverter performing charge and discharge operations in a higher efficiency interval, thereby effectively solving the problems of low efficiency and high system power consumption of the inverter under light load, and improving the overall yield of the energy storage system.

In some embodiments, the first control unit 240 includes a first control module and a jump module. The control module is used for controlling a first inversion module or a second inversion module to enter a dormant state when the load rate is judged to be smaller than a first preset threshold value, wherein the second inversion module is preferentially controlled to enter the dormant state. The skipping module is used for skipping to the step of obtaining the rated power of the inverter until the load rate is judged to be larger than or equal to a first preset threshold value.

In still other embodiments, the first control unit 240 includes a determination module and a second control module. The determining module is used for determining a corresponding first required rated power when the load rate is greater than or equal to a first preset threshold value according to the actual output power when the load rate is judged to be less than the first preset threshold value. The second control module is used for controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a dormant state according to the first required rated power so that the rated power of the inverter is equal to the first required rated power, wherein the second inversion modules are preferentially controlled to enter the dormant state.

In some embodiments, the energy storage system charge and discharge control device 200 further includes a third control unit, and the third control unit is configured to control one or more first inverter modules to be in an on state, and the second inverter modules and the remaining number of first inverter modules to be in a sleep state. The second control unit 250 includes a third control module and a fourth control module, where the third control module is configured to control at least part of the first inverter module and the second inverter module in the sleep state to enter an on state when the load factor is determined to be greater than or equal to the first preset threshold and greater than the second preset threshold, so that the load factor is greater than or equal to the first preset threshold and less than or equal to the second preset threshold. And the fourth control module is used for controlling the inverter to carry out charging and discharging work at the load rate when judging that the load rate is greater than or equal to the first preset threshold and is less than or equal to the second preset threshold.

In some embodiments, the third control module includes a first control sub-module and a skip sub-module. The first control sub-module is used for controlling a first inversion module in a dormant state or a second inversion module in the dormant state to enter an open state when judging that the load rate is greater than or equal to a first preset threshold and greater than a second preset threshold, wherein the first inversion module is preferentially controlled to enter the open state. And the skip submodule is used for skipping to the step of obtaining the rated power of the inverter until the load rate is judged to be greater than or equal to a first preset threshold value and less than or equal to a second preset threshold value.

In still other embodiments, the third control module includes a determination submodule and a second control submodule. The determining submodule is used for determining a corresponding second required rated power when the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold according to the actual output power when the load rate is greater than or equal to the first preset threshold and greater than the second preset threshold. The second control submodule is used for controlling at least part of the first inversion module and the second inversion module which are in the dormant state to enter the opening state according to the second required rated power so that the rated power of the inverter is equal to the second required rated power, and the first inversion module is preferentially controlled to enter the opening state.

In some embodiments, the energy storage system charging and discharging control placement further comprises a judging unit and a fourth control unit. The judging unit is used for judging whether the sum of the number of the first inversion modules and the number of the second inversion modules in the starting state is equal to 1. The fourth control unit is used for controlling at least one first inverter module and/or at least one second inverter module to enter an on state when the sum of the number of the first inverter modules and the number of the second inverter modules in the on state is equal to 1.

Fig. 12 is a schematic structural diagram of a computing device according to an embodiment of the present invention, and the specific embodiment of the present invention does not limit the specific implementation of the computing device.

As shown in fig. 12, the computing device may include: a processor (processor) 302, a communication Interface 304, a memory 306, and a communication bus 308.

Wherein: the processor 302, communication interface 304, and memory 306 communicate with each other via a communication bus 308. A communication interface 304 for communicating with network elements of other devices, such as clients or other servers. The processor 302 is configured to execute the program 310, and may specifically execute the relevant steps in the above embodiment of the energy storage system charge and discharge control method.

In particular, program 310 may include program code comprising computer-executable instructions.

The processor 302 may be a central processing unit CPU, or an Application Specific Integrated Circuit ASIC (Application Specific Integrated Circuit), or one or more Integrated circuits configured to implement embodiments of the present invention. The computing device includes one or more processors, which may be the same type of processor, such as one or more CPUs; or may be different types of processors such as one or more CPUs and one or more ASICs.

And a memory 306 for storing a program 310. Memory 306 may comprise high-speed RAM memory and may also include non-volatile memory (non-volatile memory), such as at least one disk memory.

The program 310 may be specifically invoked by the processor 302 to cause the computing device to perform the following operations:

acquiring the actual output power of the inverter under the condition that the power grid is connected into the charging and discharging unit or under the condition that the power of the charging and discharging unit connected into the power grid is changed;

acquiring rated power of an inverter, wherein the rated power is the sum of first rated power of a first inverter module in an on state and second rated power of a second inverter module in the on state;

determining the load rate of the inverter according to the rated power and the actual output power of the inverter;

when the load rate is judged to be smaller than a first preset threshold value, controlling at least part of the plurality of first inversion modules and the plurality of second inversion modules to enter a dormant state so as to enable the load rate to be larger than or equal to the first preset threshold value;

and when the load rate is judged to be greater than or equal to the first preset threshold, controlling the inverter to carry out charging and discharging work at the load rate.

An embodiment of the present invention provides a computer-readable storage medium, where at least one executable instruction is stored in the storage medium, and when the executable instruction is executed on a computing device, the computing device is enabled to execute the energy storage system charging and discharging control method in any method embodiment described above.

The executable instructions may be specifically configured to cause the computing device to:

and when the load rate is judged to be greater than or equal to the first preset threshold value, controlling the inverter to perform charging and discharging work at the load rate.

The algorithms or displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems may also be used with the teachings herein. The required structure for constructing such a system will be apparent from the description above. In addition, embodiments of the present invention are not directed to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present invention as described herein, and any descriptions of specific languages are provided above to disclose the best mode of the invention.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the embodiments of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the invention and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim.

Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means can be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names. The steps in the above embodiments should not be construed as limiting the order of execution unless specified otherwise.

Claims

1. The energy storage system is characterized by comprising an inverter and a power grid, wherein the inverter comprises a plurality of first inversion modules and a plurality of second inversion modules, the efficiency of the first inversion modules is greater than that of the second inversion modules, and the first inversion modules and the second inversion modules are both in an on state and a dormant state;

the method comprises the following steps:

acquiring the actual output power of the inverter under the condition that the power grid is connected into a charging and discharging unit or under the condition that the power of the charging and discharging unit connected into the power grid is changed;

acquiring rated power of the inverter, wherein the rated power is the sum of a first rated power of the first inverter module in an on state and a second rated power of the second inverter module in the on state;

when the load rate is judged to be smaller than a first preset threshold value, controlling at least part of the first inverter modules and the second inverter modules to enter a dormant state so that the load rate is larger than or equal to the first preset threshold value, wherein the second inverter modules are preferentially controlled to enter the dormant state;

when the load rate is judged to be greater than or equal to the first preset threshold value, controlling the inverter to perform charging and discharging work at the load rate;

when the load factor is judged to be smaller than a first preset threshold, controlling at least part of the plurality of first inverter modules and the plurality of second inverter modules to enter a sleep state so as to enable the load factor to be larger than or equal to the first preset threshold, including:

when the load rate is judged to be smaller than the first preset threshold, determining a corresponding first required rated power when the load rate is larger than or equal to the first preset threshold according to the actual output power;

controlling at least part of the first inverter modules and the second inverter modules to enter a sleep state according to the first required rated power so that the rated power of the inverter is equal to the first required rated power;

when the load rate is judged to be smaller than the first preset threshold, determining a corresponding first required rated power when the load rate is larger than or equal to the first preset threshold according to the actual output power; controlling at least a portion of the plurality of first inverter modules and the plurality of second inverter modules to enter a sleep state according to the first desired power rating to make the power rating of the inverter equal to the first desired power rating, including:

acquiring the first rated power Pe1 of the first inversion module and the second rated power Pe2 of the second inversion module, and determining the rated power Pe = m1Pe1+ n1Pe2 of the current inverter according to the number m1 of the first inversion modules in the current on state and the number n1 of the second inversion modules in the current on state;

if the load rate can meet the requirement that the load rate is greater than or equal to the first preset threshold value only by adjusting the number of the second inverter modules in the on state to n2, the first required rated power Pe' = m1Pe1+ n2Pe2; controlling n1-n2 second inverter modules to enter a sleep state, so that the rated power Pe of the inverter is equal to the first required rated power Pe';

if all the second inverter modules need to be adjusted to be in a sleep state, and the number of the first inverter modules in an on state needs to be adjusted to be m2 at the same time to enable the load rate to meet the requirement that the load rate is greater than or equal to the first preset threshold, the first required rated power Pe' = m2Pe1; and controlling all the second inverter modules to enter a dormant state, and controlling m1-m2 first inverter modules to carry out the dormant state, so that the rated power Pe of the inverter is equal to the first required rated power Pe'.

2. The energy storage system charging and discharging control method according to claim 1, wherein before the rated power of the inverter is obtained, the method further comprises:

controlling one or more first inversion modules to be in an on state, and controlling the second inversion module and the rest number of the first inversion modules to be in a dormant state;

when the load factor is judged to be greater than or equal to the first preset threshold value, the inverter is controlled to perform charging and discharging work at the load factor, and the method comprises the following steps:

when the load rate is judged to be greater than or equal to the first preset threshold and greater than a second preset threshold, controlling at least part of the first inversion module and the second inversion module which are in a dormant state to enter an open state, so that the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold;

and when the load rate is judged to be greater than or equal to the first preset threshold and less than or equal to the second preset threshold, controlling the inverter to carry out charging and discharging work at the load rate.

3. The energy storage system charge and discharge control method according to claim 2, wherein when it is determined that the load factor is greater than or equal to the first preset threshold and greater than a second preset threshold, controlling at least a part of the first inverter module and the second inverter module in a sleep state to enter an on state so that the load factor is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, includes:

when the load rate is judged to be greater than or equal to the first preset threshold and greater than the second preset threshold, controlling one first inversion module in a dormant state or one second inversion module in the dormant state to enter an on state, wherein the first inversion module is preferentially controlled to enter the on state;

and repeatedly executing the step of obtaining the rated power of the inverter until the load rate is judged to be greater than or equal to the first preset threshold and less than or equal to the second preset threshold.

4. The energy storage system charge and discharge control method according to claim 2, wherein when it is determined that the load factor is greater than or equal to the first preset threshold and greater than a second preset threshold, controlling at least a part of the first inverter module and the second inverter module in a sleep state to enter an on state so that the load factor is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, includes:

when the load rate is judged to be greater than or equal to the first preset threshold and greater than the second preset threshold, determining a corresponding second required rated power when the load rate is greater than or equal to the first preset threshold and less than or equal to the second preset threshold according to the actual output power;

and controlling at least part of the first inversion module and the second inversion module in the dormant state to enter an on state according to the second required rated power so that the rated power of the inverter is equal to the second required rated power, wherein the first inversion module is preferentially controlled to enter the on state.

5. The energy storage system charge-discharge control method according to any one of claims 1 to 4, characterized by further comprising:

judging whether the sum of the number of the first inversion modules and the number of the second inversion modules in the on state is equal to 1 or not;

and if so, controlling at least one first inversion module and/or at least one second inversion module to enter an opening state.

6. The energy storage system charge and discharge control device is characterized by comprising an inverter and a power grid, wherein the inverter comprises a plurality of first inversion modules and a plurality of second inversion modules, the efficiency of the first inversion modules is higher than that of the second inversion modules, and the first inversion modules and the second inversion modules are both in an open state and a dormant state;

the device comprises:

the first obtaining unit is used for obtaining the actual output power of the inverter under the condition that the power grid is connected to the charging and discharging unit or under the condition that the power of the charging and discharging unit connected to the power grid is changed;

the second obtaining unit is used for obtaining rated power of the inverter, and the rated power is the sum of first rated power of the first inverter module in an on state and second rated power of the second inverter module in the on state;

a determining unit, configured to determine a load factor of the inverter according to the rated power and the actual output power of the inverter;

the first control unit is used for controlling at least part of the first inverter modules and the second inverter modules to enter a dormant state when the load rate is judged to be smaller than a first preset threshold value, so that the load rate is larger than or equal to the first preset threshold value, and the second inverter modules are preferentially controlled to enter the dormant state;

the second control unit is used for controlling the inverter to carry out charging and discharging work at the load rate when the load rate is judged to be greater than or equal to the first preset threshold;

when the load rate is judged to be smaller than a first preset threshold value, controlling at least part of the plurality of first inverter modules and the plurality of second inverter modules to enter a sleep state so that the load rate is larger than or equal to the first preset threshold value, including:

if all the second inverter modules need to be adjusted to be in a sleep state, and the number of the first inverter modules in an on state needs to be adjusted to be m2 at the same time to enable the load rate to meet the requirement that the load rate is greater than or equal to the first preset threshold, the first required rated power Pe' = m2Pe1; and controlling all the second inversion modules to enter a dormant state, and controlling m1-m2 first inversion modules to carry out the dormant state, so that the rated power Pe of the inverter is equal to the first required rated power Pe'.

7. A computing device, comprising: the system comprises a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface complete mutual communication through the communication bus;

the memory is used for storing at least one executable instruction, and the executable instruction causes the processor to execute the operation of the energy storage system charge and discharge control method according to any one of claims 1-5.

8. A computer-readable storage medium having stored therein at least one executable instruction that, when executed on a computing device, causes the computing device to perform operations of the energy storage system charge and discharge control method according to any one of claims 1 to 5.