Automatic power regulation and control method and system of storage and charging integrated system

Abstract

The invention provides an automatic power regulation and control method and system for a storage and charging integrated system, and relates to the technical field of power grid regulation and control, and the specific scheme comprises the steps: obtaining the current working conditions of the storage and charging integrated system, including the basic load of a power distribution network, the service life attenuation of an energy storage battery, whether an electric vehicle is connected or not, and the required charging power; based on the current working condition, different operation modes are adopted, and the power distribution relation of the power distribution network, the energy storage battery and the electric vehicle is automatically distributed; wherein the different operation modes comprise a power grid friendly mode under the working condition that the basic load is higher than a load threshold value, an energy storage protection mode under the working condition that the service life attenuation is higher than a service life threshold value, and a comprehensive optimization mode under the remaining working condition; the advantages of the storage and charging integrated system are fully explored, the rapid charging requirement of the electric vehicle can be guaranteed, and battery resources can be fully utilized to support operation of the power distribution network.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grid control, and in particular relates to an automatic power control method and system for a storage-charging integrated system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, with the development of electric vehicle (EV) and plug-in hybrid vehicle (PHEV) technology, electric vehicles will gradually replace traditional vehicles and become an important means of transportation for people to travel; the charging technology of electric vehicles has received more and more attention, but the slow charging speed is one of the main reasons that restrict the further improvement of the popularity of electric vehicles; high-power charging piles are one of the main solutions to improve the charging speed. However, the charging power of high-power charging piles is relatively large, up to several hundred kilowatts, and the impact on the distribution network during operation is relatively large. The power of a high-power charging pile is equivalent to a distribution station area. Therefore, before installation, the distribution network needs to be reconstructed on a large scale, or the distribution network that can adapt to high-power charging piles needs to be redesigned and laid, resulting in high construction costs for high-power charging piles, making it difficult to popularize them on a large scale, and the number is small, which cannot meet people's growing and rapid needs.

[0004] The integrated storage and charging system combines energy storage and charging. It can store electricity in advance when the distribution network capacity is sufficient, and then discharge it at high power when charging is needed. The power is small in the process of drawing electricity from the distribution network, and the impact on the distribution network is small. Therefore, there is no need to upgrade the distribution network. It is one of the new solutions to solve the problem of fast charging in the future.

[0005] Existing power control methods for integrated storage and charging systems mostly directly merge the control schemes of the energy storage system and the fast charging system, which cannot achieve overall optimized operation, and therefore the control effect is poor. Summary of the invention

[0006] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a method and system for automatically controlling power of an integrated storage and charging system, which fully explores the advantages of the integrated storage and charging system, can not only ensure the fast charging needs of electric vehicles, but also make full use of battery resources to support the operation of the distribution network.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0008] A first aspect of the present invention provides a method for automatically controlling power of an integrated storage and charging system.

[0009] A method for automatically controlling power of a storage-charging integrated system, comprising:

[0010] Obtain the current operating conditions of the integrated storage and charging system, including the base load of the distribution network, the life decay of the energy storage battery, whether the electric vehicle is connected and the required charging power;

[0011] Based on the current working conditions, different operation modes are adopted to automatically allocate the power distribution relationship between the distribution network, energy storage batteries and electric vehicles;

[0012] Among them, the different operating modes include a grid-friendly mode under the condition that the base load is higher than the load threshold, an energy storage protection mode under the condition that the life attenuation is higher than the life threshold, and a comprehensive optimization mode under the remaining conditions.

[0013] Furthermore, the basic load of the distribution network is obtained by detecting the power of the distribution transformer;

[0014] The life attenuation of the energy storage battery is obtained through the built-in chip of the battery pack;

[0015] Whether the electric vehicle is connected and the required charging power are detected by the electric vehicle detection unit.

[0016] Further, the load threshold is a preset ratio of the rated capacity of the transformer;

[0017] The life threshold is a preset ratio of the rated capacity of the energy storage battery.

[0018] Furthermore, the grid-friendly mode is specifically:

[0019] The distribution network charges the electric vehicle through an AC-DC converter, and the energy storage battery charges the electric vehicle through a DC-DC converter simultaneously;

[0020] According to the current power supply and demand status of the distribution network, the power obtained by the AC-DC converter from the distribution network is calculated, and the remaining power is provided by the energy storage battery.

[0021] Furthermore, the energy storage protection mode is specifically:

[0022] The distribution network charges the electric vehicle through an AC-DC converter, and the energy storage battery charges the electric vehicle through a DC-DC converter simultaneously;

[0023] According to the current state of the energy storage battery, the discharge power of the energy storage battery is calculated, and the remaining power is provided by the distribution network.

[0024] Furthermore, the comprehensive optimization mode is specifically:

[0025] The distribution network, energy storage batteries, and electric vehicles form a virtual three-port system;

[0026] The electric vehicle is represented as a virtual voltage source, and the virtual voltage value is calculated;

[0027] The battery is represented as a battery virtual voltage source, and the effective value of the virtual voltage source is calculated;

[0028] The power of the distribution network and energy storage battery is automatically calculated according to circuit theory, thereby automatically allocating the power distribution relationship between the distribution network, energy storage battery and electric vehicle.

[0029] Furthermore, the power of the distribution network and the energy storage battery is automatically calculated according to the circuit theory, specifically:

[0030] The virtual voltage sources of the distribution network, energy storage battery, and electric vehicle are subtracted and divided by the preset virtual impedance value to finally obtain the virtual current value. The virtual current value is multiplied by the virtual voltage to obtain the power value.

[0031] A second aspect of the present invention provides an automatic control power system for an integrated storage and charging system.

[0032] An automatic power control system for a storage-charging integrated system includes an acquisition module and a control module:

[0033] The acquisition module is configured to: acquire the current working condition of the storage-charging integrated system, including the basic load of the distribution network, the life attenuation of the energy storage battery, whether the electric vehicle is connected and the required charging power;

[0034] The control module is configured to: automatically allocate the power distribution relationship among the power distribution network, energy storage battery, and electric vehicle based on the current working conditions and in different operation modes;

[0035] Among them, the different operating modes include a grid-friendly mode under the condition that the base load is higher than the load threshold, an energy storage protection mode under the condition that the life attenuation is higher than the life threshold, and a comprehensive optimization mode under the remaining conditions.

[0036] The third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of a method for automatically controlling power of an integrated storage and charging system as described in the first aspect of the present invention.

[0037] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for automatically controlling power of an integrated storage and charging system as described in the first aspect of the present invention are implemented.

[0038] One or more of the above technical solutions have the following beneficial effects:

[0039] In addition to the original basic functions of charging and energy storage, the storage-charging integrated system of the present invention also adds an automatic power control method. Based on the basic load of the distribution network and the life attenuation of the energy storage battery, the corresponding "grid-friendly mode", "energy storage protection mode", and "comprehensive optimization mode" are adopted to break the inherent operating mode of slow charging and fast discharging. The power distribution relationship between the distribution network, battery, and electric vehicle in the storage-charging integrated system of the above structure can be automatically allocated without advance setting. This method can fully explore the advantages of the storage-charging integrated system, which can not only ensure the fast charging needs of electric vehicles, but also make full use of battery resources to support the operation of the distribution network.

[0040] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0042] Figure 1 This is a flow chart of the method of the first embodiment.

[0043] Figure 2 This is a structural diagram of the storage-charging integrated system of the first embodiment. DETAILED DESCRIPTION

[0044] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] Embodiment 1

[0047] In one embodiment of the present disclosure, a method for automatically controlling power of a storage-charging integrated system is provided, such as Figure 1 As shown, the following steps are included:

[0048] Step S1: Obtain the current operating conditions of the integrated storage and charging system, including the basic load of the distribution network, the life attenuation of the energy storage battery, whether the electric vehicle is connected and the required charging power.

[0049] Furthermore, the basic load of the distribution network is obtained by detecting the power of the distribution transformer;

[0050] The life attenuation of the energy storage battery is obtained through the built-in chip of the battery pack;

[0051] Whether the electric vehicle is connected and the required charging power are detected by the electric vehicle detection unit.

[0052] Step S2: Based on the current working conditions, different operation modes are adopted to automatically allocate the power distribution relationship among the distribution network, energy storage batteries, and electric vehicles.

[0053] Among them, the different operating modes include a grid-friendly mode under the condition that the base load is higher than the load threshold, an energy storage protection mode under the condition that the life attenuation is higher than the life threshold, and a comprehensive optimization mode under the remaining conditions.

[0054] Further, the load threshold is a preset ratio of the rated capacity of the transformer;

[0055] The life threshold is a preset ratio of the rated capacity of the energy storage battery.

[0056] Furthermore, the grid-friendly mode is specifically:

[0057] The distribution network charges the electric vehicle through an AC-DC converter, and the energy storage battery charges the electric vehicle through a DC-DC converter simultaneously;

[0058] According to the current power supply and demand status of the distribution network, the power obtained by the AC-DC converter from the distribution network is calculated, and the remaining power is provided by the energy storage battery.

[0059] Furthermore, the energy storage protection mode is specifically:

[0060] The distribution network charges the electric vehicle through an AC-DC converter, and the energy storage battery charges the electric vehicle through a DC-DC converter simultaneously;

[0061] According to the current state of the energy storage battery, the discharge power of the energy storage battery is calculated, and the remaining power is provided by the distribution network.

[0062] Furthermore, the comprehensive optimization mode is specifically:

[0063] The distribution network, energy storage batteries, and electric vehicles form a virtual three-port system;

[0064] The electric vehicle is represented as a virtual voltage source, and the virtual voltage value is calculated;

[0065] The battery is represented as a battery virtual voltage source, and the effective value of the virtual voltage source is calculated;

[0066] The power of the distribution network and energy storage battery is automatically calculated according to circuit theory, thereby automatically allocating the power distribution relationship between the distribution network, energy storage battery and electric vehicle.

[0067] Furthermore, the power of the distribution network and the energy storage battery is automatically calculated according to the circuit theory, specifically:

[0068] The virtual voltage sources of the distribution network, energy storage battery, and electric vehicle are subtracted and divided by the preset virtual impedance value to finally obtain the virtual current value. The virtual current value is multiplied by the virtual voltage to obtain the power value.

[0069] The following is a detailed description of the implementation process of the automatic power control method of the storage-charging integrated system in this embodiment.

[0070] Storage and charging integrated system, such as Figure 2 As shown, it includes distribution network, energy storage battery and electric vehicle. The difference from traditional high-power charging piles is that energy storage battery is added, which integrates energy storage and charging. When the capacity of distribution network is abundant, electricity is stored in energy storage battery in advance, and then discharged at high power when electric vehicle needs to be charged.

[0071] In addition to the original basic functions of charging and energy storage, the integrated storage and charging system will also incorporate the control method described in this embodiment. Based on the basic load of the distribution network and the life decay of the energy storage battery, the corresponding operation mode is adopted to break the inherent operation mode of slow charging and fast discharging. The power distribution relationship between the distribution network, battery, and electric vehicle in the integrated storage and charging system of the above structure can be automatically allocated without advance setting. This method can fully explore the advantages of the integrated storage and charging system, which can not only ensure the fast charging needs of electric vehicles, but also make full use of battery resources to support the operation of the distribution network.

[0072] Specifically, this embodiment adopts the mutual cooperation of the fast charging unit, the bidirectional energy storage unit, the power grid detection unit, the battery detection unit, the electric vehicle detection unit and the power allocation unit to realize the regulation of the storage and charging integrated system; wherein, the fast charging unit is used to convert the high-voltage direct current into the direct current required for charging the electric vehicle, the bidirectional energy storage unit is used to realize the charging and discharging management of the energy storage battery, the power grid detection unit is used to detect the voltage information of the distribution network, the battery detection unit is used to detect the power and life of the battery, so as to calculate the life attenuation of the battery, the electric vehicle detection unit is used to detect whether the electric vehicle is connected and the required charging power, and the power allocation unit is used to use the AC-DC converter and the DC-DC converter to allocate the power flow and power size among the power grid, the energy storage battery and the electric vehicle.

[0073] The storage and charging integrated system detects the real-time voltage of the current distribution network through the above-mentioned power grid detection unit, and judges the power supply and demand status in the distribution network based on the normalized voltage, that is, high voltage indicates power reverse transmission, power surplus, low voltage indicates that power needs to be obtained from the power grid, power is insufficient; by detecting the battery terminal voltage, the capacity of the existing battery is judged based on the normalized battery terminal voltage; the required capacity of the electric vehicle is detected, and converted into a virtual terminal voltage based on the normalized capacity, as shown in formula (4). According to the supply and demand relationship of power generation and consumption in the distribution network, when the basic load of the distribution network is high, the "grid friendly mode" is adopted; when the energy storage life decays more, the "energy storage protection mode" is adopted; for other working conditions, the "comprehensive optimization mode" is adopted.

[0074] When the basic load of the power grid is high, the "grid-friendly mode" is adopted, and the judgment standard for high load can be set by yourself, for example: exceeding 70% of the rated capacity of the transformer; the basic load of the power grid is obtained by detecting the power of the distribution transformer.

[0075] When the energy storage life decays significantly, the "energy storage protection mode" is adopted. The judgment standard for the energy storage life decay can be set by yourself, for example: the energy storage capacity decays to 90% of the rated capacity; the battery life decay can be obtained through the built-in chip of the battery pack.

[0076] For other working conditions, the “comprehensive optimization mode” is adopted.

[0077] When operating in "grid-friendly mode", the operation steps of the storage-charging integrated system include:

[0078] (1-1) The power grid charges the electric vehicle through an AC-DC converter and the energy storage battery charges the electric vehicle through a DC-DC converter. The DC-DC converter controls the DC voltage and the AC-DC converter controls the power obtained from the power grid. At this time, the energy storage battery is responsible for ensuring the charging voltage of the electric vehicle, and the energy on the grid side is determined by the operating status of the grid (i.e., the power supply and demand status).

[0079] (1-2) The maximum power taken from the power grid is defined as PGmax, the maximum allowable value of the effective value of the grid phase voltage is VGmax, and the minimum allowable value is VGmin. The AC-DC converter calculates the power PG obtained from the grid by the AC-DC converter control according to the current grid phase voltage effective value VG collected. The calculation formula is:

[0080] PG = PGmax*(VG-VGmin) / (VGmax-VGmin) (1)

[0081] At this time, the integrated storage and charging system can automatically calculate the power according to the power supply and demand status of the distribution network, and the remaining power is provided by the energy storage system. When the grid voltage is high, the energy supply of the distribution network exceeds the demand, and the system obtains more power from the grid; conversely, when the grid voltage is low, the energy supply of the distribution network is less than the demand, and the system obtains less power from the grid, reducing the impact on the grid.

[0082] When operating in the "energy storage protection mode", the operation steps of the storage and charging integrated system include:

[0083] (2-1) The power grid charges the electric vehicle through an AC-DC converter and the energy storage battery charges through a DC-DC converter. The AC-DC converter controls the DC voltage and the DC-DC converter controls the power obtained from the energy storage. At this time, the power grid ensures the charging voltage of the electric vehicle through the AC-DC converter, and the discharge power of the battery is determined by the battery status.

[0084] (2-2) Define the cycle life of the energy storage battery as CBmax, the number of energy storage cycles detected by the integrated storage and charging system (i.e., the number of battery charge and discharge cycles) as CB, the maximum storage capacity of the energy storage as Bmax, the minimum storage capacity as Bmin, and the currently detected storage capacity as B. The calculation formula for the battery discharge power PB at this time is:

[0085] PB=PBrated*[(B-Bmin) / (Bmax-Bmin)]*(CB / CBmax) (2)

[0086] Among them, PBrated is the rated discharge power of the battery.

[0087] At this time, the more battery cycles there are and the lower the battery power is, the smaller the discharge power is, thereby reducing the rate at which the battery life is consumed.

[0088] When operating in the "comprehensive optimization mode", the operation steps of the storage and charging integrated system include:

[0089] (3-1) The power grid, battery, and electric vehicle form a virtual three-port system.

[0090] (3-2) The electric vehicle is represented as a virtual voltage source, the maximum power of the charging pile is PCmax, and the required power of the electric vehicle is PC. Then the effective value VVC of the equivalent virtual voltage source of the electric vehicle is expressed as:

[0091] VVC=VVCmin+a*PC / PCmax(3)

[0092] Among them, VVCmin represents the minimum value of the virtual voltage source of the electric vehicle, which means the virtual voltage size when the electric vehicle is not charging. According to circuit theory, the virtual voltage size is equal to the average value of the effective value of the grid voltage and the battery virtual voltage source; a is the virtual voltage droop coefficient, and its specific value can be set by yourself.

[0093] (3-3) The battery is represented as a battery virtual voltage source, and the effective value VVB of the virtual voltage source is expressed as:

[0094] VVB=VVBmin+b*CB / CBmax(4)

[0095] Among them, VVBmin represents the minimum value of the battery virtual voltage source, and b is the virtual voltage droop coefficient, and its specific value can be set by oneself.

[0096] (3-4) The system consisting of the power grid, battery, and electric vehicle is equivalent to a circuit consisting of a virtual voltage source and an electric network. The power flow and magnitude can be automatically calculated based on circuit theory, thereby automatically adjusting the power of the power grid, battery, and electric vehicle. The specific power calculation method is:

[0097] The virtual voltage sources of the power grid, battery, and electric vehicle are subtracted and divided by the virtual impedance value to finally obtain the virtual current value. The virtual current value is multiplied by the virtual voltage to obtain the power value. The virtual impedance value can be set by yourself.

[0098] Embodiment 2

[0099] In one embodiment of the present disclosure, an automatic power control system of a storage-charging integrated system is provided, including an acquisition module and a control module:

[0100] The acquisition module is configured to: acquire the current working condition of the storage-charging integrated system, including the basic load of the distribution network, the life attenuation of the energy storage battery, whether the electric vehicle is connected and the required charging power;

[0101] The control module is configured to: automatically allocate the power distribution relationship among the power distribution network, energy storage battery, and electric vehicle based on the current working conditions and in different operation modes;

[0102] Among them, the different operating modes include a grid-friendly mode under the condition that the base load is higher than the load threshold, an energy storage protection mode under the condition that the life attenuation is higher than the life threshold, and a comprehensive optimization mode under the remaining conditions.

[0103] Embodiment 3

[0104] The purpose of this embodiment is to provide a computer-readable storage medium.

[0105] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in a method for automatically controlling power of an integrated storage and charging system as described in Embodiment 1 of the present disclosure.

[0106] Embodiment 4

[0107] The purpose of this embodiment is to provide an electronic device.

[0108] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for automatically controlling power of an integrated storage and charging system as described in the first embodiment of the present disclosure are implemented.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for automatically controlling power of an integrated storage and charging system. It is characterized in that include: Obtain the current operating conditions of the integrated storage and charging system, including the base load of the distribution network, the life decay of the energy storage battery, whether the electric vehicle is connected and the required charging power; Based on the current working conditions, different operation modes are adopted to automatically allocate the power distribution relationship between the distribution network, energy storage batteries and electric vehicles; Among them, the different operating modes include a grid-friendly mode under the condition that the base load is higher than the load threshold, an energy storage protection mode under the condition that the life attenuation is higher than the life threshold, and a comprehensive optimization mode under the remaining conditions.

2. The automatic power control method of the storage-charging integrated system according to claim 1, It is characterized in that The basic load of the distribution network is obtained by detecting the power of the distribution transformer; The life attenuation of the energy storage battery is obtained through the built-in chip of the battery pack; Whether the electric vehicle is connected and the required charging power are detected by the electric vehicle detection unit.

3. The automatic power control method of the storage-charging integrated system according to claim 1, It is characterized in that The load threshold is a preset ratio of the rated capacity of the transformer; The life threshold is a preset ratio of the rated capacity of the energy storage battery.

4. The automatic power control method of the storage-charging integrated system according to claim 1, It is characterized in that The grid-friendly mode is specifically: The distribution network charges the electric vehicle through an AC-DC converter, and the energy storage battery charges the electric vehicle through a DC-DC converter simultaneously; According to the current power supply and demand status of the distribution network, the power obtained by the AC-DC converter from the distribution network is calculated, and the remaining power is provided by the energy storage battery.

5. The automatic power control method of the storage-charging integrated system according to claim 1, It is characterized in that The energy storage protection mode is specifically: The distribution network charges the electric vehicle through an AC-DC converter, and the energy storage battery charges the electric vehicle through a DC-DC converter simultaneously; According to the current state of the energy storage battery, the discharge power of the energy storage battery is calculated, and the remaining power is provided by the distribution network.

6. The automatic power control method of the storage-charging integrated system according to claim 1, It is characterized in that The comprehensive optimization mode is specifically: The distribution network, energy storage batteries, and electric vehicles form a virtual three-port system; The electric vehicle is represented as a virtual voltage source, and the virtual voltage value is calculated; The battery is represented as a battery virtual voltage source, and the effective value of the virtual voltage source is calculated; The power of the distribution network and energy storage battery is automatically calculated according to circuit theory, thereby automatically allocating the power distribution relationship between the distribution network, energy storage battery and electric vehicle.

7. The automatic power control method of the storage-charging integrated system as claimed in claim 6, It is characterized in that The automatic calculation of the power of the distribution network and the energy storage battery according to the circuit theory is specifically as follows: The virtual voltage sources of the distribution network, energy storage battery, and electric vehicle are subtracted and divided by the preset virtual impedance value to finally obtain the virtual current value. The virtual current value is multiplied by the virtual voltage to obtain the power value.

8. An automatic power control system for an integrated storage and charging system, It is characterized in that Including acquisition module and control module: The acquisition module is configured to: acquire the current working condition of the storage-charging integrated system, including the basic load of the distribution network, the life attenuation of the energy storage battery, whether the electric vehicle is connected and the required charging power; The control module is configured to: automatically allocate the power distribution relationship among the power distribution network, energy storage battery, and electric vehicle based on the current working conditions and in different operation modes; Among them, the different operating modes include a grid-friendly mode under the condition that the base load is higher than the load threshold, an energy storage protection mode under the condition that the life attenuation is higher than the life threshold, and a comprehensive optimization mode under the remaining conditions.

9. An electronic device, Its characteristics include: a memory for non-transitory storage of computer readable instructions; a processor for executing the computer-readable instructions; When the computer-readable instructions are executed by the processor, the method described in any one of claims 1 to 7 is executed.

10. A storage medium, Its characteristics are: The computer-readable instructions are non-transitorily stored, wherein when the computer-readable instructions are executed by a computer, the method of any one of claims 1 to 7 is performed.

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