CN117713165A - Energy management device and energy management system - Google Patents

Abstract

The present application provides an energy management device comprising: gateway and energy storage device. The energy storage device is used for being electrically connected with the load and the alternating current power grid, and the energy storage device adjusts charging power or discharging power based on control signals of the gateway. The gateway is used for receiving a detection signal, and the detection signal is used for indicating the actual output power of the alternating current power grid; in response to the actual output power being greater than the target power, sending a first control signal to the energy storage device, the first control signal being used to instruct the energy storage device to reduce the charging power or increase the discharging power; and in response to the actual output power being less than the target power, sending a second control signal to the energy storage device, the second control signal being used to instruct the energy storage device to reduce the discharge power or increase the charge power. The total load power can be accurately controlled by adjusting the charging and discharging power of the energy storage device through the real-time output power and the target power of the alternating current power grid, so that the output power of the alternating current power grid approaches the target power, and the reliability of power supply is improved.

Description

Energy management device and energy management system

Technical Field

The present application relates to the field of power technology, and in particular, to an energy management device and an energy management system.

Background

With the global increased interest and demand for renewable energy sources, more and more distributed energy sources such as solar, wind power, and energy storage systems are widely used, for example, lithium-ion energy storage systems are deployed in a large number of communication base stations. To better integrate and manage these decentralized energy resources, virtual power plant (virtual power plants, VPP) technologies have evolved.

Devices deployed with distributed energy sources participate in auxiliary services of the virtual power plant by controlling the total load power variation in the devices in an aggregate manner, and the devices can obtain benefits and reduce electricity cost by responding to the demands of the virtual power plant. In order to participate in auxiliary services of the virtual power plant, the equipment deployed with the distributed energy source needs to control the total load power of the equipment, wherein the total load power of the equipment comprises power consumption of a direct current load inside the equipment and power of an energy storage device, and specifically, when the equipment deployed with the distributed energy source receives a target power instruction of the virtual power plant, the total load power of the equipment needs to be controlled to meet the target power.

However, there is a real-time change in the power consumption of the dc load in the device, and how to accurately control the total load power of the device to meet the target power becomes a problem to be solved.

Disclosure of Invention

The application provides an energy management device and an energy management system, through which charging and discharging of an energy storage device can be controlled to control total load power of equipment, so that the total load power of the equipment meets target power, and auxiliary services of a virtual power plant are participated in to reduce electricity consumption cost.

In a first aspect, there is provided an energy management device comprising: gateway and energy storage device. The energy storage device is used for being electrically connected with the load and the alternating current power grid, and the energy storage device is used for adjusting charging power or discharging power based on a control signal of the gateway. The gateway is used for receiving a detection signal, and the detection signal is used for indicating the actual output power of the alternating current power grid; in response to the actual output power being greater than the target power, sending a first control signal to the energy storage device, the first control signal being used to instruct the energy storage device to reduce the charging power or increase the discharging power; and in response to the actual output power being less than the target power, sending a second control signal to the energy storage device, the second control signal being used to instruct the energy storage device to reduce the discharge power or increase the charge power.

It should be understood that in the embodiments of the present application, the energy storage device may be regarded as a part of the total load of the apparatus, and since the energy storage device is connected to both the ac power grid and the load, the ac power grid is electrically connected to the load, so that the output power of the ac power grid is equal to the sum of the charging and discharging power of the energy storage device and the power of the load, and the charging and discharging power of the energy storage device refers to the charging power or the discharging power of the energy storage device, and the energy storage device can only be in a charging state or a discharging state in a time.

In the present application, the target power refers to a target output power of an ac power grid, and the target power may be set according to an actual requirement, for example, the target power is set to a smaller value in a period of higher electricity price, and the target power is set to a larger value in a period of lower electricity price.

According to the scheme, the gateway in the energy management device can adjust the charge and discharge power of the energy storage device according to the real-time output power and the target power of the alternating current power grid, and the total load power of the equipment can be accurately controlled by adjusting the charge and discharge power of the energy storage device, so that the output power of the alternating current power grid approaches the target power, and the reliability of power supply of the base station is improved.

With reference to the first aspect, in certain implementations of the first aspect, before sending the first control signal or the second control signal to the energy storage device, the gateway is further configured to send a third control signal to the energy storage device, where the third control signal is configured to instruct the energy storage device to adjust the power to 0 to keep the energy storage device in a state of not charging and not discharging, and instruct the energy storage device to adjust the remaining power percentage to a set value.

The set value of the remaining capacity percentage of the energy storage device may be determined according to specific use requirements, and for example, the set value may be 50%.

In the scheme, the power of the energy storage device is kept to be 0 before adjustment, the percentage of the residual electric quantity of the energy storage device is a set value, and the phenomenon that the adjustment is not timely or the adjustment quantity exceeds the range due to too large adjustment amplitude when the charge and discharge power of the energy storage device is adjusted can be avoided, so that the reliability of power supply is improved.

With reference to the first aspect, in some implementations of the first aspect, the gateway is further configured to receive an adjustment signal sent by the network manager, where the adjustment signal is used to indicate a power deviation amount, where the power deviation amount is determined by the network manager based on an actual output power of the ac power grid after adjusting charging power or discharging power of the energy storage device sent by the plurality of gateways and target powers corresponding to the plurality of gateways, and the network manager is communicatively connected to the plurality of gateways; and sending a fourth control signal to the energy storage device, wherein the fourth control signal is used for indicating the change amount of the charging power or the discharging power of the energy storage device as the power deviation amount.

In one possible implementation, the target power is sent to the gateway by the gateway.

In the scheme, after the energy storage device is adjusted, the gateway can further adjust the charge and discharge power of the energy storage device according to the adjustment conditions of other equipment, so that the reasonable distribution of electric energy in the whole power supply system is realized, the power supply efficiency is improved, and the electricity consumption cost is reduced.

With reference to the first aspect, in some implementations of the first aspect, the gateway is further configured to obtain an actual output power of the ac power grid after adjusting the charging and discharging power of the energy storage device, and send the actual output power to a network manager, where the network manager covers the plurality of base stations.

By reporting the output power of the regulated AC power grid, an adjustment result can be fed back to the network manager, so that the network manager can conveniently perform subsequent control, and the real-time performance and accuracy of the control are improved.

With reference to the first aspect, in certain implementations of the first aspect, the gateway communicates with the network manager through an IP protocol.

With reference to the first aspect, in certain implementations of the first aspect, the gateway is communicatively connected to the energy storage device through a CAN.

With reference to the first aspect, in certain implementations of the first aspect, the gateway is communicatively connected to the detection unit through RS 485.

In a second aspect, there is provided an energy management system comprising: a network management and at least one first aspect and energy management devices in its implementation form. Wherein the network manager is in communication with the energy management device. The network manager is configured to send a control signal to the at least one energy management device, the control signal being configured to indicate a target power of the ac power grid.

With reference to the second aspect, in some implementations of the second aspect, the network manager is further configured to receive an actual output power of the ac power grid after the charging and discharging powers of the energy storage devices are adjusted, where the actual output power is sent by the at least one energy management device.

With reference to the second aspect, in some implementations of the second aspect, the network manager is further configured to send an adjustment signal to the energy management device, where the adjustment signal is used to indicate a power deviation amount, and the power deviation amount is determined based on an actual output power of the ac power grid after the charging and discharging power of the energy storage device is adjusted and a target power of the ac power grid corresponding to the at least one energy management device, which are sent by the at least one energy management device.

With reference to the second aspect, in certain implementations of the second aspect, the energy management device communicates with the network management device via an IP protocol.

Drawings

Fig. 1 shows a schematic diagram of an application scenario provided in the present application.

Fig. 2 shows a schematic structural diagram of a communication device provided in the present application.

Fig. 3 shows a logic diagram for adjusting charge and discharge power of an energy storage device according to the present application.

Fig. 4 shows a logic diagram of still another embodiment of the present application for regulating the charge and discharge power of an energy storage device.

Detailed Description

The technical solutions in the present application will be described below with reference to the accompanying drawings.

Fig. 1 shows a schematic diagram of an application scenario provided in the present application. The application can be an energy management system, can be applied to a VPP scene, and as shown in fig. 1, a network manager can serve a plurality of first devices, can establish communication with the plurality of first devices, and can be electrically connected with an alternating current power grid.

Illustratively, the network manager establishes a communication connection with the first device via a 4G or IP protocol.

In the embodiment of the application, the network management comprises a cloud platform for aggregating and managing the distributed site gateway.

Illustratively, the network management may include a cloud energy management system (energy management system, EMS).

In the embodiment of the application, the network manager can monitor, control and optimize the distribution and use of the electric energy in the first equipment, and can monitor and control the running state and the energy flow mode of the energy storage device in each first equipment so as to realize the effective management of the electric energy. Specifically, the energy storage device can dynamically adjust the operation mode and the energy distribution mode of the energy storage device according to the supply condition of renewable energy sources and the demand condition of a power grid, so that the supply and demand balance is realized, and the utilization efficiency of the renewable energy sources is improved. The system can monitor the load condition of the power grid and the supply condition of the power, and automatically adjust the charge and discharge time and current of the energy storage device according to the requirements so as to balance the supply and demand relationship and ensure the stable operation of the power system.

The network manager can adjust the operation mode and the energy distribution mode of the energy storage device based on peak clipping and valley filling, and when the energy storage device is in a power consumption peak section, the network manager can adjust the energy storage device into a discharge mode and reduce the power of an distributed alternating current power grid; when the energy storage device is in the electricity utilization valley section, the electricity price is lower, and the network manager can adjust the energy storage device to be in a charging mode and increase the power of the distributed alternating current power grid.

In the embodiment of the application, the device where the distributed energy source is deployed is referred to as a first device, and the first device may be a communication device including an energy storage device or a consumer load including a photovoltaic power generation system by way of example. A schematic structure of the first device will be described below with reference to fig. 2 by taking a communication device as an example.

Fig. 2 shows a schematic block diagram of a communication device provided in the present application, including but not limited to a base station or the like for performing wireless communication.

As shown in fig. 2, the communication apparatus includes an energy management device, a detection unit, and a load. The energy management device is used for controlling the total load power of the communication equipment, the detection unit is used for detecting the actual output power of the alternating current power grid, and the actual output power of the alternating current power grid is equal to the total load power of the communication equipment. The energy management device is in communication with the network management device of fig. 1, the load is in electrical connection with the ac power grid, and the energy management device is in electrical connection with the connection point of the load and the ac power grid.

The load may comprise electronics or equipment such as a base station that needs to be operated by electrical energy, for example, the load is operated under direct current and the load is rated at 48 volts.

In one possible implementation, the communication device further comprises a power converter through which the AC power grid is electrically connected to the load, and through which the AC power grid is further electrically connected to the energy storage device, the power converter illustratively comprising an AC-to-DC (alternating current to direct current, AC/DC) converter for converting AC power input by the AC power grid to DC power for use by the load or converting AC power input by the AC power grid to DC power for storage in the energy storage device, the power converter further comprising a DC-to-DC (direct current to direct current, DC/DC) converter for converting, on the one hand, a voltage of the DC power output by the AC/DC converter to an operating voltage of the load or the energy storage device, and, on the other hand, for stabilizing the DC power output by the AC/DC converter by the DC/DC converter.

The energy management device comprises a gateway and an energy storage device, wherein the gateway is in communication connection with the energy storage device, and the energy storage device is electrically connected with a connection point of the load and the alternating current power grid.

In this embodiment of the present application, the total power of the communication device is determined by the load and the energy storage device, and it should be understood that in this embodiment of the present application, the energy storage device may store electric energy from the ac power grid, and may also release electric energy to the load, so the power of the energy storage device may be divided into charging power and discharging power, which are simply referred to as charging and discharging power.

In one possible scenario, the ac power grid provides power to the load and the energy storage device, the energy storage device is in a charged state, and the total load power of the communication device is the power of the load plus the charging power of the energy storage device.

In one possible scenario, the ac power grid and the energy storage device provide power to the load, the energy storage device is in a discharged state, and the total load power of the communication device is the power of the load minus the discharge power of the energy storage device.

The energy storage device can be in communication connection with the gateway and can adjust the charge and discharge power of the energy storage device according to the signal of the gateway.

The energy storage device comprises an intelligent lithium battery, and the energy storage device and the gateway establish communication connection through the CAN.

The energy storage device comprises a battery side power converter comprising a plurality of DC/DC converters, i.e. one battery side power converter may also be referred to as one DC/DC converter bank, and a plurality of batteries (clusters). The battery-side power converter is used for power conversion of a plurality of batteries (clusters), for example, charge control and discharge control.

In one possible implementation, the energy storage device further comprises a controller for controlling the DC/DC conversion circuit to adjust the charging power or the discharging power of the energy storage device based on the signal of the gateway.

In this embodiment of the present application, a gateway refers to a device or a system located inside a communication device, and is used to connect and coordinate an edge device and a network in the communication device, so as to implement data aggregation, processing, and forwarding. The gateway may be in communication connection with the network management in fig. 1, and may also be in communication connection with the detection unit. The gateway can obtain target power of the alternating current power grid from the network management, and obtain actual output power of the alternating current power grid from the detection unit, and further, the network management can adjust charging and discharging power of the energy storage device according to the target power of the alternating current power grid and the actual output power of the alternating current power grid.

Illustratively, the detection unit is an electricity meter and the gateway establishes communication with the detection unit via RS 485.

It should be noted that, in fig. 2, the communication device includes one load only as an example, the number of loads in the communication device is not limited in this application, and, for example, if the communication device includes a plurality of loads, the communication device may further include a power divider, where an input end of the power divider is connected to an output end of the power converter, an input end of the power converter is connected to the ac power grid, and an input end of the power divider is connected to a bus-side port of the battery-side power converter. Specifically, the input terminal of the power divider includes a positive input terminal connected to the positive bus bar and a negative input terminal connected to the negative bus bar. The plurality of output ends of the power divider are respectively connected with the plurality of loads in a one-to-one correspondence manner, so that the power divider can output direct current input from the input end to each load through each output port. In addition, the power distributor can also realize the functions of short-circuit protection, overvoltage protection and the like.

It should be noted that, the communication device in fig. 2 includes one energy storage device only as an example, the number of energy storage devices in the communication device is not limited in this application, and whether the energy storage devices are connected in series or in parallel is not limited.

It should be noted that the communication device in fig. 2 is only an example of the first device in the present application, and the specific kind of the first device is not limited in the present application.

In fig. 2, the energy management device may adjust the total load power of the communication device, specifically, the energy management device adjusts the total load power of the communication device by adjusting the charge and discharge power of the energy storage device, and fig. 3 shows a logic diagram for adjusting the charge and discharge power of the energy storage device provided in the present application, where the energy management device is located in the first device.

As shown in fig. 3, the gateway obtains a target power of the ac power grid, which is equivalent to the total load power of the first device.

In one possible implementation, the network manager sends an adjustment signal to the gateway, where the adjustment signal includes a target power of the ac power grid in the first device, and the adjustment signal may be, for example, a peak regulation command or a frequency regulation command, where if the control signal is the frequency regulation command, the gateway controls the power of the energy storage device to be 0 to keep the energy storage device in a state of not being charged and not being discharged, and controls a remaining capacity (SOC) percentage of the energy storage device to be a set value.

In the application, the energy storage device is controlled to be in a state of no charge and no discharge, and the purpose of controlling the SOC of the energy storage device to be a set value is to prevent untimely adjustment or out-of-range adjustment caused by too large adjustment amplitude when adjusting the charge and discharge power of the energy storage device, wherein the set value of the SOC percentage can be set according to actual needs.

Illustratively, the set point for the SOC percentage of the energy storage device is 50%.

It should be noted that, in the embodiment of the present application, the gateway sends the control signal to the energy storage device to control the charging power or the discharging power of the energy storage device, and the energy storage device may adjust the charging power or the discharging power based on the control signal.

The energy storage device includes a controller, a battery device, and a DC/DC converter having one end electrically connected to the battery device and the other end electrically connected to the load and the ac power grid, the controller being configured to control the DC/DC converter based on a control signal of the gateway to adjust a charging power or a discharging power of the energy storage device.

The gateway also obtains the actual output power of the ac power grid, and in a possible implementation, the gateway receives a detection signal sent by the detection unit, where the detection signal is used to indicate the actual output power of the ac power grid.

The gateway adjusts the charging and discharging power of the energy storage device based on the detection signal and the adjustment signal. Specifically, if the actual output power of the ac power grid is greater than the target power of the ac power grid, the gateway sends a first control signal to the energy storage device, where the first control signal is used to instruct the energy storage device to reduce the charging power or increase the discharging power; if the actual output power of the alternating current power grid is smaller than the target power of the alternating current power grid, the gateway sends a second control signal to the energy storage device, and the second control signal is used for indicating the energy storage device to reduce the discharging power or increase the charging power.

The gateway obtains the actual output power of the regulated AC power grid through the detection unit, and the gateway can repeat the actions according to the actual output power of the regulated AC power grid until the actual output power of the AC power grid is equal to the target power of the AC power grid.

It should be noted that, the method and the basis for determining the target power of the ac power grid are not limited in this embodiment, for example, the target power of the ac power grid may be determined according to the first device participating in off-the-shelf market peak shifting, demand side response, peak shaving, frequency modulation, peak clipping and valley filling, and the like.

In the above scheme, the gateway in the capacity management device can control the charge and discharge power of the energy storage device in a closed loop manner according to the actual output power and the target power of the alternating current power grid, so as to control the total load power of the first equipment, enable the output power of the alternating current power grid to approach the target power, and improve the reliability of power supply of the first equipment. By introducing the actual output power of the alternating current power grid, the control accuracy reduction caused by the load transmission change can be avoided, and the accuracy is improved.

Fig. 3 is directed to output power of an ac power grid in a single first device, and as can be seen in fig. 1, a network manager can serve multiple first devices at the same time, that is, the network manager can communicate with multiple gateways, where there may be a part of gateways that fail to timely adjust actual output power of the ac power grid due to a fault, so that total output power of the ac power grid in a system formed by the multiple first devices does not meet a preset target. The network manager can integrate the output power of the alternating current power grid in the first devices so as to optimize the total output power of the alternating current power grid in the system formed by the first devices. Fig. 4 shows a logic diagram for adjusting the charge and discharge power of the energy storage device provided by the present application.

As shown in fig. 4, the network manager receives the actual output power of the ac power grid sent by the N gateways, where each gateway corresponds to the actual output power of one ac power grid.

In one possible implementation, the actual output power of the ac power grid transmitted by the N gateways is the actual output power of the ac power grid adjusted by the N gateways through fig. 3.

The network manager obtains the target power sum of the alternating current power grids corresponding to the N gateways.

In one possible implementation, the network manager obtains the target power sums of the ac power grids corresponding to the N gateways from the VPP.

The network manager determines the deviation amount according to the actual output power of the alternating current power grid sent by the N gateways and the target power sum of the alternating current power grid corresponding to the N gateways, and specifically, the deviation amount can be determined by summing the actual output power of the alternating current power grid sent by the N gateways and the target power sum of the alternating current power grid corresponding to the N gateways.

The network manager selects M gateways, the deviation amount is distributed to the M gateways, the M gateways send control signals to the energy storage device according to the deviation amount to instruct the energy storage device to adjust charging and discharging power, the adjusted transformation amount is the deviation amount sent by the network manager, so that the sum of actual output power of the alternating current power grid sent by the N gateways is equal to the target power sum of the alternating current power grid corresponding to the N gateways, and M is a positive integer smaller than or equal to N.

It should be noted that, in the present application, the method for selecting M gateways by the network manager is not limited, and, by way of example, the network manager may select from low to high according to the priority, or may select randomly.

It should be appreciated that fig. 4 and 3 do not conflict and that fig. 4 may be trimmed based on the adjustment of fig. 3.

In the scheme, the gateway can further adjust the charge and discharge power of the energy storage device according to the conditions of other first equipment, so that reasonable distribution of electric energy in the whole first equipment system is realized, the power supply efficiency is improved, and the electricity cost is reduced.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a network management, or a network device, etc.) to perform all or part of the steps of the method described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (12)

1. An energy management device, comprising:

a gateway and an energy storage device;

the energy storage device is used for being electrically connected with a load and an alternating current power grid, and is used for adjusting charging power or discharging power based on a control signal of the gateway;

the gateway is used for the purpose of,

receiving a detection signal, said detection signal being indicative of an actual output power of said ac power grid,

in response to the actual output power being greater than a target power, sending a first control signal to the energy storage device, the first control signal being used to instruct the energy storage device to decrease charge power or increase discharge power,

and in response to the actual output power being less than the target power, sending a second control signal to the energy storage device, wherein the second control signal is used for instructing the energy storage device to reduce the discharge power or increase the charge power.

2. The energy management device of claim 1, wherein the gateway is further configured to,

and sending a third control signal to the energy storage device, wherein the third control signal is used for indicating the energy storage device to adjust the power to 0 so as to keep the energy storage device in a state of no charge and no discharge, and indicating the energy storage device to adjust the percentage of the residual electric quantity to be a set value.

3. The energy management device of claim 1 or 2, wherein the gateway is further configured to,

receiving an adjusting signal sent by a network manager, wherein the adjusting signal is used for indicating a power deviation amount, the power deviation amount is determined by the network manager based on the actual output power of the alternating current power grid after the charging power or the discharging power of the energy storage device is adjusted and the target power corresponding to a plurality of gateways, and the network manager is in communication connection with the gateways;

and sending a fourth control signal to the energy storage device, wherein the fourth control signal is used for indicating that the change amount of the charging power or the discharging power of the energy storage device is the power deviation amount.

4. The energy management device of any of claims 1-3, wherein the gateway is further configured to,

and acquiring the actual output power of the alternating current power grid after the energy storage device adjusts the charging power or the discharging power, and sending the actual output power to a network manager.

5. The energy management device of claim 3 or 4, wherein the gateway communicates with the network management via an IP protocol.

6. The energy management device of any of claims 1-5, wherein the gateway is communicatively connected to the energy storage device via CAN.

7. The energy management device of any of claims 1 to 6, wherein the gateway is communicatively connected to a detection unit for detecting the actual output power of the ac power grid via RS 485.

8. The energy management device of any of claims 1-7, wherein the target power is sent by a gateway to the gateway.

9. An energy management system, comprising: a network management and at least one energy management device according to any one of claims 1 to 8;

the network manager is in communication connection with at least one of the energy management devices;

the network manager is used for sending control signals to at least one energy management device, and the control signals are used for indicating target power of an alternating current power grid.

10. The energy management system of claim 9, wherein the network manager is further configured to receive an actual output power of the ac power grid after the energy storage device is adjusted to charge and discharge power sent by the at least one energy management device.

11. The energy management system of claim 10, wherein the network manager is further configured to send an adjustment signal to the energy management device, the adjustment signal being configured to indicate a power deviation amount, the power deviation amount being determined based on an actual output power of the ac power grid after the adjustment of the charging and discharging power of the energy storage device sent by the at least one energy management device and a target power of the ac power grid corresponding to the at least one energy management device.

12. The energy management system of any of claims 9 to 11, wherein the energy management device communicates with the network management device via an IP protocol.