CN111740401A

CN111740401A - Multi-feed-in low-voltage direct current distribution method, device, system and controller

Info

Publication number: CN111740401A
Application number: CN202010780837.8A
Authority: CN
Inventors: 王国英; 张东辉; 戴晓曈
Original assignee: Beijing Zhongqing Zhihui Energy Technology Co ltd
Current assignee: Beijing Zhongqing Zhihui Energy Technology Co ltd
Priority date: 2020-08-06
Filing date: 2020-08-06
Publication date: 2020-10-02
Anticipated expiration: 2040-08-06
Also published as: CN111740401B

Abstract

The application provides a multi-feed-in low-voltage direct-current power distribution method, device, system and controller. The method comprises the following steps: the controller obtains the residual capacity of each feed-in power grid after supplying power to the alternating current load through a detector arranged on the feeder line. The controller determines the remaining capacity as a capacity value of the feed-in grid. According to the capacity value and the power supply requirement, the controller determines the power supply power fed into each power grid. And the controller determines the power supply power of the AC-DC converter corresponding to each feed-in power grid according to the power supply power of each feed-in power grid. And the controller controls the AC-DC converter to input electric energy to the DC distribution network according to the power supply power and realizes power supply to the DC load. The method increases the reliability of the power distribution system and improves the resource utilization rate of the power distribution network.

Description

Multi-feed-in low-voltage direct current distribution method, device, system and controller

Technical Field

The present disclosure relates to power distribution technologies, and in particular, to a multi-feed low-voltage dc power distribution method, apparatus, system, and controller.

Background

The distribution network is used for receiving electric energy of a power transmission network or a regional power plant and distributing the electric energy on site through distribution facilities or distributing the electric energy to various users step by step according to voltage. A low voltage distribution network is located at the very end of the distribution system for distributing 380V power to various types of loads. At present, in a low-voltage distribution network, a low-voltage distribution network formed by a transformer and a power supply load of each power supply station area is not electrically connected with low-voltage distribution networks of other station areas.

As the applications of various high-power loads at the user end increase, the randomness of the use of the high-power loads is also increased. Consequently, significant load fluctuations are easily caused to the low-voltage distribution network. In the prior art, a manner of increasing the reservation margin is used for solving the technical problem. In the prior art, the effect of keeping the voltage of the low-voltage distribution network stable when a high-power load is randomly connected is realized through a reserved large margin.

However, the above-mentioned manner of reserving the margin has the problems of resource waste, low resource utilization rate, and the like.

Disclosure of Invention

The application provides a multi-feed-in low-voltage direct-current power distribution method, device, system and controller, which are used for solving the problems of resource waste, low resource utilization rate and the like in the prior art.

In a first aspect, the present application provides a multi-feed low-voltage dc power distribution system, comprising:

each feed-in power grid is connected to the direct-current power distribution network through an alternating-current-direct-current converter;

the controller is connected with the direct current power distribution network, is used for controlling output parameters of the alternating current-direct current converter according to input parameters of the feed-in power grids so as to stabilize working parameters of the direct current power distribution network, and is connected to the direct current power distribution network through cables or optical fibers;

the direct current distribution network is provided with at least one output port, and the output port is used for being connected with an external direct current load.

Optionally, the method further comprises: a switch;

the switch is used for controlling connection or disconnection of a joining device, wherein the joining device comprises at least one of the feeding power grid, the direct current load, a bus and a cable, and the bus or the cable is used for connecting the alternating current-direct current converter, an output port and the direct current load.

Optionally, the dc load comprises an energy storage power station;

the energy storage power station is used for storing energy when the power resources of the direct current power distribution network are sufficient and releasing energy when the power resources of the direct current power distribution network are in short supply.

Optionally, the dc load comprises a charging station;

the charging station is used for sending charging information of the charging vehicle to the controller, so that the controller determines the charging condition of the charging vehicle according to the charging information.

Optionally, the feed grid comprises a transformer, a feeder and an ac load.

Optionally, the topology structure of the dc distribution network is any one of a ring network structure, a star structure, and a radiation structure.

In a second aspect, the present application provides a multi-feed low-voltage dc power distribution method, including:

acquiring the capacity value of each feed-in power grid, wherein the capacity value is the residual capacity of the feed-in power grid after supplying power to the alternating current load of the feed-in power grid;

determining the power supply power of each AC-DC converter according to the capacity value of each feed-in power grid and a first power supply requirement;

and supplying power to the direct current load according to the power supply power.

Optionally, the determining the power supply power of each ac-dc converter according to the capacity value and the first power supply requirement of each feeding grid includes:

determining a first preset value according to the first power supply requirement;

and determining the power supply power of each AC-DC converter according to the first preset value, the capacity value of each feed-in power grid and the first power supply requirement.

Optionally, when the capability value of each feed-in grid is greater than or equal to a first preset value, the determining the power supply power of each ac-dc converter according to the first preset value, the capability value of each feed-in grid, and the first power supply requirement includes at least one of:

determining a first average power supply requirement as the power supply power of each AC-DC converter according to the first power supply requirement, wherein the first average power supply requirement is the quotient of the first power supply requirement divided by the number of fed power grids;

determining the power supply power of each AC-DC converter according to the first power supply requirement and the capacity value proportion of each feed-in power grid, wherein the capacity value proportion is the ratio of the capacity value of one feed-in power grid to the sum of the capacity values of all feed-in power grids;

and determining the power supply power of each AC-DC converter according to the first power supply requirement, the capacity value of each feed-in power grid and the priority of each feed-in power grid.

Optionally, when the capability value of the fed-in power grid is smaller than the first preset value and larger than or equal to a second preset value, determining that the fed-in power grid with the capability value smaller than the first preset value and larger than or equal to the second preset value is a first power grid, and determining that the fed-in power grid with the capability value larger than or equal to the first preset value is a second power grid, wherein the first preset value is larger than the second preset value;

determining the power supply power of each ac-dc converter according to the first preset value, the capability value of each feeding grid and the first power supply requirement, including:

determining a first power supply power of the corresponding AC-DC converter according to the capacity value of each feed-in power grid of the first power grid;

determining a second power supply requirement of the second power grid according to the first power supply power and the first power supply requirement;

and determining a second power supply power of the corresponding AC-DC converter according to the second power supply requirement and the capacity value of each feed-in power grid of the second power grid.

Optionally, the determining a second power supply power of the corresponding ac-dc converter according to the second power supply requirement and the capability value of the second power grid includes at least one of:

determining a second average power supply requirement as the power supply power of the corresponding AC-DC converter according to the second power supply requirement, wherein the second average power supply requirement is the quotient of the second power supply requirement divided by the number of feed-in power grids of a second power grid;

determining the corresponding power supply power of the AC-DC converter according to the second power supply requirement and the capacity value proportion of each feed-in power grid of the second power grid, wherein the capacity value proportion is the ratio of the capacity value of one feed-in power grid of the second power grid to the sum of the capacity values of all feed-in power grids of the second power grid;

and determining the corresponding power supply power of the AC-DC converter according to the second power supply requirement, the capacity value of each feed-in power grid of the second power grid and the priority of the second power grid.

Optionally, the method comprises:

when the capacity value of the fed-in power grid is smaller than a second preset value, determining that the fed-in power grid with the capacity value smaller than the second preset value is a third power grid, and determining that the fed-in power grid with the capacity value larger than or equal to a first preset value is a second power grid, wherein the first preset value is larger than the second preset value;

determining the power supply power of each AC-DC converter according to the capacity value and the first power supply requirement of each feed-in power grid, wherein the determining comprises the following steps:

determining a third power supply power of the corresponding AC-DC converter according to the capacity value of the third power grid, wherein the third power supply power is used for supplying power to an AC load fed into the power grid;

and determining fourth power supply power of the corresponding AC-DC converter according to the third power supply power and the capacity value of each feed-in power grid of the second power grid.

Optionally, the determining a fourth power supply of the corresponding ac-dc converter according to the third power supply and the capability value of each feeding grid of the second grid includes:

determining a total compensation amount according to the third power supply power;

and determining the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of each feed-in power grid of the second power grid.

Optionally, the determining the fourth supply power of the corresponding ac-dc converter according to the total compensation amount and the capability value of each feeding grid of the second grid includes at least one of:

determining an average compensation quantity as the power supply power of the corresponding AC-DC converter according to the total compensation quantity, wherein the average compensation quantity is the quotient of the total compensation quantity divided by the number of the feed-in power grids of the second power grid;

determining the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value proportion of each feed-in power grid of the second power grid, wherein the capacity value proportion is the ratio of the capacity value of one feed-in power grid of the second power grid to the sum of the capacity values of all feed-in power grids of the second power grid;

and determining the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount, the capacity value of each feed-in power grid of the second power grid and the priority of each feed-in power grid of the second power grid.

Optionally, the dc load comprises an energy storage power station, and the method comprises:

acquiring the statistical capacity value of the capacity value of each feed-in power grid in each time period;

determining an energy storage time period according to the statistical capacity value and a preset capacity value;

adjusting the power supply power of the AC-DC converter according to the energy storage time period, the energy storage of the energy storage power station and the capacity value of each feed-in power grid;

and storing energy in the energy storage power station according to the adjusted power supply power.

Optionally, the dc load comprises a charging station, and the method comprises:

acquiring charging information of a charging vehicle in the charging station, wherein the charging information of the charging vehicle is sent to the controller by the charging station;

determining the use conditions of the charging station and the charging vehicle according to the charging information;

and when the charging station or the charging vehicle is abnormal, sending alarm information, wherein the alarm information is used for reminding an administrator that the charging station or the charging vehicle is abnormal.

In a third aspect, the present application provides a multi-feed low-voltage dc power distribution apparatus, comprising:

the first acquisition module is used for acquiring the capacity value of each feed-in power grid, wherein the capacity value is the residual capacity of the feed-in power grid after the feed-in power grid supplies power to the alternating current load of the feed-in power grid;

the first determining module is used for determining the power supply power of each AC-DC converter according to the capacity value and the first power supply requirement of each feed-in power grid;

and the power supply module is used for supplying power to the direct current load according to the power supply power.

Optionally, the first determining module includes:

the first determining submodule is used for determining a first preset value according to the first power supply requirement;

and the second determining submodule is used for determining the power supply power of each AC-DC converter according to the first preset value, the capacity value of each feed-in power grid and the first power supply requirement.

Optionally, when the capability values of the respective feeding grids are greater than or equal to a first preset value, the second determining submodule is specifically configured to execute at least one of:

the second determining submodule is specifically configured to determine, according to the capability values of the respective feed-in power grids of the first power grid, a corresponding first power supply power of the ac-dc converter; determining a second power supply requirement of the second power grid according to the first power supply power and the first power supply requirement; and determining a second power supply power of the corresponding AC-DC converter according to the second power supply requirement and the capacity value of each feed-in power grid of the second power grid.

Optionally, when the capability value of the fed-in power grid is smaller than a second preset value, determining that the fed-in power grid with the capability value smaller than the second preset value is a third power grid, and determining that the fed-in power grid with the capability value larger than or equal to a first preset value is a second power grid, wherein the first preset value is larger than the second preset value;

the first determining module includes:

the third determining submodule is used for determining corresponding third power supply power of the alternating current-direct current converter according to the capacity value of the third power grid, and the third power supply power is used for supplying power to an alternating current load fed into the power grid;

and the fourth determining submodule is used for determining the corresponding fourth power supply power of the AC-DC converter according to the third power supply power and the capability values of the fed-in power grids of the second power grid.

Optionally, the fourth determining module is specifically configured to determine a total compensation amount according to the third power supply; and determining the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of each feed-in power grid of the second power grid.

Optionally, the dc load comprises an energy storage power station, and the apparatus comprises:

the statistical module is used for acquiring the statistical capacity value of the capacity value of each feed-in power grid in each time period;

the second determining module is used for determining an energy storage time period according to the statistical capacity value and a preset capacity value;

the adjusting module is used for adjusting the power supply power of the AC-DC converter according to the energy storage time period, the energy storage of the energy storage power station and the energy values of all the fed-in power grids;

and the power supply module is used for storing energy for the energy storage power station according to the adjusted power supply power.

Optionally, the dc load comprises a charging station, and the apparatus comprises:

the second acquisition module is used for acquiring the charging information of the charging vehicles in the charging station, and the charging information of the charging vehicles is sent to the controller by the charging station;

the third determining module is used for determining the use conditions of the charging station and the charging vehicle according to the charging information;

and the alarm unit is used for sending alarm information when the charging station or the charging vehicle is abnormal, wherein the alarm information is used for reminding an administrator that the charging station or the charging vehicle is abnormal.

In a fourth aspect, the present application provides a controller comprising: the system comprises a communication input/output interface, an arithmetic processor and a human-computer interface;

the communication interface is used for acquiring input parameters of each device of the multi-feed-in low-voltage direct-current power distribution system, wherein the input parameters comprise current, voltage or running state, and the communication interface is also used for outputting control instructions and parameter output parameters to each device of the multi-feed-in low-voltage direct-current power distribution system;

the processor is used for executing the multi-feed low-voltage direct current power distribution method in any one possible design of the second aspect and the second aspect;

and the human-computer interface is used for realizing interaction between the multi-feed-in low-voltage direct-current power distribution system and an administrator, wherein the interaction comprises the steps of acquiring the settings of the administrator and outputting abnormal alarm information to the administrator.

According to the multi-feed-in low-voltage direct-current power distribution method, the device, the system and the controller, the detector arranged on the feeder line is used for obtaining the residual capacity of each feed-in power grid after supplying power to the alternating-current load, and determining the residual capacity as the capacity value of the feed-in power grid; determining the power supply power of each feed-in power grid according to the capacity value and the power supply requirement; determining the power supply power of the AC-DC converter corresponding to each feed-in power grid according to the power supply power of each feed-in power grid; according to the power supply power, the AC-DC converter is controlled to input electric energy to the DC distribution network, and a means for supplying power to the DC load is realized, so that the interconnection and the energy complementation of the electric energy among the feed-in power grids are realized, the reliability of the multi-feed-in low-voltage DC distribution system under the condition of small margin is improved, and the effect of improving the resource utilization rate of the distribution network is realized.

Drawings

In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is an application scenario diagram of a multi-feed low-voltage dc power distribution system according to an embodiment of the present application;

fig. 2 is a flowchart of a multi-feed low-voltage dc power distribution method according to an embodiment of the present application;

fig. 3 is a flowchart of another multi-feed low-voltage dc power distribution method according to an embodiment of the present application;

fig. 4 is a flowchart of another multi-feed low-voltage dc distribution method according to an embodiment of the present application;

fig. 5 is a flowchart of another multi-feed low-voltage dc distribution method according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a multi-feed-in low-voltage dc power distribution apparatus according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of a multi-feed low-voltage dc power distribution system according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a controller according to an embodiment of the present application.

Detailed Description

To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the drawings in the present application, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The technical solution of the present application will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

The distribution network is an electric power network which receives electric energy from a transmission network or a regional power plant and distributes the electric energy to various users on site through distribution facilities or step by step according to voltage. A low voltage distribution network is located at the very end of the distribution system for distributing 380V power to various types of loads. At present, in a low-voltage distribution network, a low-voltage distribution network consisting of a transformer and a power supply load of each power supply station area is not electrically connected with low-voltage distribution networks of other station areas.

In power distribution networks, power supply reliability is among the most critical and direct parts. When the load is stable, the installed capacity of the transformer is basically matched with the capacity of the load when the power distribution network is used. As the use of various high power loads increases, the randomness of the use of high power loads also increases. Random joining and breaking of high-power loads easily causes obvious load fluctuation of a low-voltage distribution network. In order to ensure the stability of the power distribution network, a large margin needs to be reserved when the load is configured, so as to avoid the problem of power supply overload which can be generated when extreme fluctuation conditions are met.

However, reserving a larger margin results in a waste of electrical energy and a reduction in overall performance. In order to solve the problem, the application provides a multi-feed-in low-voltage direct-current power distribution system. The multi-feed low-voltage direct-current power distribution system comprises a direct-current power distribution network and a plurality of feed power grids. In the multi-feed low-voltage direct-current power distribution system, a plurality of feed power grids are connected into a direct-current power distribution network together. Through interconnection and intercommunication of a plurality of feed-in power grids, the effect of ensuring the voltage stability of the direct-current power distribution network is achieved when high-power loads are randomly connected or disconnected.

In the existing high-power load, the occupation ratio of the direct current load is higher and higher. In practical use, since high-power loads are usually individually connected to the distribution network, the ac-dc converters of these dc loads are usually installed at the respective equipment terminals. However, when a large number of dc loads exist in one power distribution network, each dc load performs ac-dc conversion, which causes problems of waste of power resources and a bottleneck in use efficiency. In order to solve the problem, in the multi-feed low-voltage direct-current power distribution system provided by the application, an alternating-current direct-current converter is added on a feed power grid side. The feed-in network is connected to the DC distribution network through an AC-DC converter. The alternating current fed into the power grid is converted into direct current through the alternating current-direct current converter, and the direct current power distribution grid is supplied with power. The direct current distribution can directly supply direct current to the direct current load, thereby reducing the loss of electric energy in the alternating current-direct current conversion process of each direct current load and avoiding the problem of service efficiency bottleneck.

In practice, the feed network is usually also connected with an ac load before being connected to the dc distribution network. The energy consumption of the alternating current load makes the electric energy fed into the power grid and fed into the direct current distribution network have instability. There may even be a problem that the power fed into the grid cannot meet the power consumption of the ac load. In order to solve the problem, in the multi-feed low-voltage direct-current power distribution system used in the application, forward mutual aid and reverse mutual aid of electric energy are realized by controlling the electric energy flow of each feed-in power grid, so that the power supply reliability of the multi-feed low-voltage direct-current power distribution system is improved.

For example, when a certain feeding grid is overloaded due to its own abnormality or an ac load, the feeding grid supplies insufficient power to the dc distribution grid. At this moment, the stability of the direct-current power distribution network can be ensured by increasing the power supply power of other feed-in power grids connected into the direct-current power distribution network. Or, in an extreme case, when a certain feed-in power grid exits from operation due to a fault of the certain feed-in power grid or the alternating current load is heavily overloaded, the feed-in power grid cannot supply power to the direct current load, and the requirement for supplying power to the alternating current load may not be met. In this case, the dc distribution network can supply the ac loads, which are fed into the grid, via the ac-dc converter.

In addition, a large-capacity lithium battery can be configured in the direct-current power distribution network. When alternating current loads and/or direct current loads in the multi-feed low-voltage direct current distribution system are in peak values, the high-capacity lithium battery can release energy to the alternating current loads and/or the direct current loads. When alternating current load and/or direct current load are in the valley in the multi-feed-in low-voltage direct current distribution system, idle electric energy can be stored through a high-capacity lithium battery. Through this large capacity lithium cell, the timesharing of electric energy is multiplexing can be realized to many feed-in low pressure direct current distribution system, improves distribution equipment utilization ratio, improves the power supply reliability.

Fig. 1 shows an application scenario diagram of a multi-feed low-voltage dc power distribution system according to an embodiment of the present application. The application scenario is an electric vehicle charging station (megawatt level) installed with a plurality of large-capacity electric vehicle charging stations. Besides the large-capacity electric vehicle charging station, other types of direct current loads and energy storage power stations can be installed in the electric vehicle charging station.

Since the electric vehicle charging station is used with high randomness, a problem of significant load fluctuation is likely to occur. Meanwhile, since the electric vehicle charging stations are generally dc loads, if each electric vehicle charging station performs electric energy conversion, there may be problems of a bottleneck in use efficiency, electric energy waste, and the like. Therefore, the multi-feed-in low-voltage direct-current power distribution system can effectively improve the stability of the power distribution network and the electric energy utilization rate of the power distribution network by aiming at the scene.

As shown in fig. 1, the multi-feed low-voltage dc power distribution system includes N feed grids. The feed-in network comprises a transformer, which may be a three-phase transformer. One end of the three-phase transformer is connected with the output end of the power transmission network or the regional power plant and is used for obtaining 10kV output electric energy output by the power transmission network or the regional power plant. The three-phase transformer is used for converting the 10kV electric energy into 380V electric energy required by an alternating current load or a direct current load. The other end of the three-phase transformer is connected with a 380V feeder line. The feeder line is connected with the AC-DC converter, the three-phase transformer and the AC load and is used for transmitting 380V electric energy among the three.

The alternating current load is various electric equipment connected to the feed-in power grid. For example, the three-phase transformer feeding the grid may be connected to a cell by a feeder. The ac load may comprise electrical equipment in the homes of the residents in the cell, or electrical equipment in a public area of the cell. As another example, the three-phase transformer feeding the grid may be connected to an industrial park by a feeder. The ac load may include various instruments within the industrial park.

Each feed-in network is connected to a dc distribution network via an ac-dc converter. The AC-DC converter is used for converting electric energy according to the output parameters. The output parameters include current conversion direction, power supply and the like. For example, when the current conversion direction is from ac to dc, the ac-dc converter converts ac fed into the grid into dc according to the power supply and outputs the dc to the dc distribution grid. For another example, when the current conversion direction is from dc to ac, the ac-dc converter converts the dc in the dc distribution network into ac according to the power supply power, and supplies power to the ac load.

As shown in fig. 1, the dc distribution network adopts a ring network configuration. And N alternating current-direct current converters corresponding to the N feed-in power grids are connected with the direct current distribution network. At least one output port is connected to the dc distribution network, and each output port is connected to a dc load. The application scene comprises M electric vehicle charging stations, an energy storage power station and other direct current loads or power supplies. When the electric vehicle charging station is used, the N feed grids supply power to the dc distribution grid via the respective ac-dc converters.

Each feed-in network is connected with a respective ac load. Different ac loads have different power consumption, and therefore, different feeding grids have different residual capacities after supplying power to the ac loads. The controller may determine an output parameter of the ac-dc converter based on the remaining capacity. The AC-DC converter realizes the conversion of AC and DC according to the output parameters, thereby realizing the reasonable distribution of power resources.

The peak-to-valley variation of the power consumption is usually periodic for different ac loads. For example, the electricity consumption of residents of a cell is generally concentrated in the daytime and the night time is generally a low-valley period of the electricity consumption. And the electricity utilization condition of the electric automobile charging station and the peak-valley period of the residential electricity have certain overlap. Therefore, when the power consumption of the alternating current load and the direct current load is in the valley period, the energy storage power station can obtain redundant electric energy to store energy. When the power consumption of the alternating current load and the direct current load is large and the electric energy is in shortage, the energy storage power station can release energy to be used by the alternating current load or the direct current load.

In the application, in the multi-feed-in low-voltage direct-current power distribution system, the controller realizes control of the multi-feed-in low-voltage direct-current power distribution system by acquiring the input parameters and determining the output parameters and the control instructions according to the output parameters. Therefore, the present application uses the controller as an execution main body to execute the multi-feed low-voltage dc power distribution method of the following embodiments. Specifically, the controller may be an electronic device with computing capability, such as a computer, a server, a microprocessor, or the like.

Fig. 2 shows a flowchart of a multi-feed low-voltage dc power distribution method according to an embodiment of the present application. On the basis of the embodiment shown in fig. 1, as shown in fig. 2, with the controller as the main execution body, the method of this embodiment may include the following steps:

s101, obtaining the capacity value of each feed-in power grid, wherein the capacity value is the residual capacity of the feed-in power grid after power is supplied to an alternating current load of the feed-in power grid.

In this embodiment, the multi-feed low-voltage dc distribution system may include at least one detector. The controller obtains the capacity value of each feed-in power grid through the detectors. Wherein the detector may be mounted on a feeder line feeding the power grid.

Specifically, the detector may obtain an amount of power output by the transformer to the ac load. The detector sends the detection value to the controller. And the controller determines the residual capacity according to the output electric quantity of each transformer fed into the power grid. The controller determines the capacity value of each feed-in power grid according to the residual capacity.

In one implementation, the detector may send the detected values to the controller in real time.

In another implementation, the detector may send the detected value at the current time to the controller when the controller requests the detected value therefrom.

And S102, determining the power supply power of each AC-DC converter according to the capacity value of each feed-in power grid and the first power supply requirement.

In this embodiment, the controller determines the capability value of each feeding grid according to S101. The nature of this capacity value is the remaining capacity after feeding the grid to supply the ac load. The residual capacity is the electric quantity which can be supplied to the direct current distribution network by each feed-in power grid.

The power supply demand is the power consumption demand of the direct current load in the direct current distribution network. The power supply requirement is determined according to the power consumption of the direct current load connected in the direct current distribution network. For example, the larger the number of electric vehicle charging stations used in the dc distribution network, the larger the amount of electric power required by the dc distribution network.

The controller distributes the power supply demand to each of the feed grids according to the remaining capacity of the respective feed grid. Furthermore, the controller determines the power supply power of the ac-dc converter of each feeding network according to the power supply requirement of each feeding network.

For example, assume that the power consumption of each electric vehicle charging station is 10. When an electric vehicle charging station is started, the electric vehicle charging station sends a power supply demand to the controller, and the demand is 10. When the direct current distribution network is connected with two feed-in power grids, and the residual capacity of each feed-in power grid is 5, the controller determines that the power supply power of each feed-in power grid is 5.

In one example, as more dc loads are added to the dc distribution grid, the dc loads on the dc distribution grid increase and the power demand increases. And the controller adjusts the power supply power of each AC-DC converter according to the power supply requirement so that the electric quantity of the DC distribution network meets the power consumption requirement of the DC load.

For example, assume that the power consumption of each electric vehicle charging station is 10. At a first time, an electric vehicle charging station is activated. At this time, the power supply demand of the dc distribution network is 10. When the dc distribution network is connected to two feeding grids and the remaining capacity of each feeding grid is 10, the controller determines that the supply power of each feeding grid is 5. At a second time, another electric vehicle charging station is activated. At this time, the power supply demand of the dc distribution network is updated to 20. When the direct current distribution network is connected with two feed-in power grids and the residual capacity of each feed-in power grid is 10, the controller recalculates the power supply power of the two feed-in power grids. The controller determines that the power supplied to each feeding network is 10.

In one example, when the power supply power is less than the power demand of the dc load, the power supply of part of the dc load is disconnected.

In this example, since the ac loads are connected to the feeder grids, there may be a case where the remaining capacity of the feeder grids is small. In an extreme case, after a plurality of feed-in power grids supply power to the dc distribution network, the power of the dc distribution network still cannot meet the power demand of the dc load. At this time, the controller controls a certain DC load to disconnect from the DC distribution network. Alternatively, the controller reduces the amount of power supplied by the dc distribution network to a dc load.

For example, assume that the power consumption of each electric vehicle charging station is 10. There are two electric vehicle charging stations that are activated. At this time, the power supply demand of the dc distribution network is 20. When the dc distribution network is connected to two feed-in power grids and the remaining capacity of each feed-in power grid is 5, the power supply amounts of the two feed-in power grids cannot meet the power demand of the dc load. The controller selects one electric vehicle charging station to supply power according to the use requirements of the two electric vehicle charging stations, and disconnects the other electric vehicle charging station.

And S103, supplying power to the direct current load according to the power supply power.

In this embodiment, the controller sends the power supply power and an instruction to start power supply to the ac-dc converter, so as to instruct the ac-dc converter to supply power according to the power supply power. And the direct current distribution network outputs the electric energy to a corresponding direct current load according to the power supply requirement.

For example, it is assumed that the dc distribution network is connected to three feeder grids, wherein the three feeder grids are a feeder grid 1, a feeder grid 2, and a feeder grid 3, respectively. According to step S102, the controller determines that the feed-in grid 1 and the feed-in grid 2 respectively supply power to the dc distribution grid, with the supply power being 5. The feed network 3 does not supply power to the dc distribution network. At this time, the controller transmits the power supply power and the instruction to start power supply to the ac-dc converters corresponding to the feeder grid 1 and the feeder grid 2, respectively. And the AC-DC converters corresponding to the feed-in power grid 1 and the feed-in power grid 2 start to supply power to the DC distribution network according to the instruction.

The application provides a multi-feed-in low-voltage direct-current power distribution method. The controller obtains the residual capacity of each feed-in power grid after supplying power to the alternating current load through a detector arranged on the feeder line. The controller determines the remaining capacity as a capacity value of the feed-in grid. According to the capacity value and the power supply requirement, the controller determines the power supply power fed into each power grid. And the controller determines the power supply power of the AC-DC converter corresponding to each feed-in power grid according to the power supply power of each feed-in power grid. And the controller controls the AC-DC converter to input electric energy to the DC distribution network according to the power supply power and realizes power supply to the DC load. In the application, the controller can realize interconnection and mutual energy complementation of electric energy among the feed-in power grids by acquiring the residual capacity of each feed-in power grid after supplying power to the alternating current load, so that the reliability of the multi-feed-in low-voltage direct current power distribution system under the condition of small margin is ensured, and the effect of improving the resource utilization rate of the power distribution network is realized.

During the conventional power utilization process, when the electric energy of the distribution network is insufficient to support the load in the distribution network, a mode of disconnecting a partial load is generally adopted to ensure the normal operation of most loads or ensure the normal operation of important loads. However, in the present application, the multi-feed low-voltage dc power distribution system uses a multi-feed structure. In the multi-feed structure, interconnection and mutual communication of electric energy and mutual energy compensation are realized among a plurality of feed power grids. By the energy mutual-aid mode, the problem of insufficient power supply power of other fed-in power grids can be solved by increasing part of power supply power fed into the power grids, so that the stability of the direct-current power distribution network is ensured. The specific example steps of this approach are as follows.

Fig. 3 shows a flowchart of another multi-feed low-voltage dc power distribution method according to an embodiment of the present application. On the basis of the embodiments shown in fig. 1 and fig. 2, as shown in fig. 3, with a controller as an execution subject, the method of the present embodiment includes the following steps:

s201, obtaining the capacity value of each feed-in power grid, wherein the capacity value is the residual capacity of the feed-in power grid after power is supplied to an alternating current load of the feed-in power grid.

Step S201 is similar to the step S101 in the embodiment of fig. 2, and this embodiment is not described herein again.

S202, determining a first preset value according to the first power supply requirement.

In this embodiment, the controller obtains the capability value of each feeding power grid according to step S201. The controller is also configured to obtain a power demand of the dc load prior to determining the supply power. According to the power consumption requirement, the controller determines the power supply requirement of the direct current distribution network. According to the power supply requirement, the controller determines a first preset value. The first preset value is a larger capacity value, and when the capacity value fed into the power grid is larger than or equal to the first preset value, the fed-in power grid has enough electric energy to supply power to the direct-current distribution network.

Specifically, the first preset value is a capability value greater than 0. E.g., 5, 10, etc., whose values are determined by the power requirements.

For example, assuming that the power supply requirement is 10 and the number of the fed power grids is 2, the first preset value may be 8, 9, 10, etc

And S203, determining the power supply power of each AC-DC converter according to the first preset value, the capacity value of each fed power grid and the first power supply requirement.

In this embodiment, the controller compares the ability value of each fed-in power grid with the first preset value. And the controller determines the power supply power of each AC-DC converter according to the comparison result and by combining the capacity value of each fed-in power grid.

In one example, when the capacity value of each feeding grid is greater than or equal to the first preset value, the controller determines the power supply power of each ac-dc converter directly according to the capacity value and the power supply demand of each feeding grid.

In one implementation, the first average power supply requirement is determined as the power supply power of each ac-dc converter according to the first power supply requirement, where the first average power supply requirement is a quotient obtained by dividing the first power supply requirement by the number of fed power grids, and the calculating step may specifically include:

step 1, the controller calculates a first average power supply requirement, and the calculation formula is as follows:

first average power supply demand = power supply demand/number of fed-in power grids

And 2, determining the first average power supply requirement as the power supply power of each AC-DC converter by the controller.

In another implementation, the power supply power of each ac-dc converter is determined according to the first power supply requirement and a specific gravity of a capacity value of each fed-in grid, where the specific gravity of the capacity value is a ratio of a capacity value of one fed-in grid to a sum of capacity values of all fed-in grids, and the calculating step may specifically include:

step 1, calculating capacity value specific gravity of each feed-in power grid by using a controllerW _i. Where i is used to represent the ith feed grid, i =1, 2, …, N. The capacity value of each feed-in grid can be expressed asC _i. Wherein the content of the first and second substances,W _ithe calculation formula of (a) may be specifically expressed as:

step 2, the controller compares the capacity value of each feed-in power grid with the specific gravityW _iThe product of the power supply requirement D as the power supply of each AC-DC converterP _i. Wherein the content of the first and second substances,P _ithe calculation formula of (a) may be specifically expressed as:

in another implementation, the power supply power of each ac-dc converter is determined according to the first power supply requirement, the capability value of each feeding grid and the priority of each feeding grid, and the calculating step may include:

step 1, the controller sequences all feed-in power grids according to the priority of all feed-in power grids.

In this step, the priority of each feed-in power grid is used to express the priority of the feed-in power grid for distributing power to the dc distribution network. The feeding grid with high priority can be the AC load with lower equipment priority or the AC load with lower power demand in the period.

For example, the controller may directly set the priority of the feeder grid when the feeder grid accesses the multi-feeder low voltage dc distribution system. The priority setting can be determined by the manager on the basis of the respective ac load fed into the grid. When the ac load fed into the grid is important, the priority of the feeding grid to access the dc distribution grid is low. For example, when the ac load fed into the power grid is a street lamp, the power supply priority of the power supply device is higher. Therefore, the priority of the feed power grid to access the direct current distribution network is lower.

For example, the controller may count the capacity values of each feed grid at each time period. The controller can determine the priority of each feed-in power grid according to the current time period and the statistical rule of each feed-in power grid. The controller may determine that the higher priority of the higher statistical power value fed into the grid is higher in the current time period. The statistical capacity value of the feed-in power grid in the current time period is high, which shows that the power consumption demand of the alternating current load fed into the power grid is low in the current time period, so that the power supply quantity capable of supplying power to the direct current distribution network is large.

For example, the priority may also be determined in order according to the capability values of the respective feeding grids acquired by the controller. The controller may determine that the high priority of feeding into the grid is high.

And 2, determining the power supply power of each AC-DC converter one by the controller from high to low according to the priority. Therefore, the feed-in power grid with low priority is guaranteed, power can be supplied to the alternating current load preferentially, and the problem of insufficient power supply caused by load fluctuation of the alternating current load is avoided.

In this step, for each ac-dc converter, the controller may determine the supply power directly from the capability value. For example, when the power value fed into the grid is 10, the controller may determine that the supply power of the ac-dc converter is 10, 9, 8, etc. The value may be a capacity value fed into the grid, or the value may be a value slightly smaller than the capacity value fed into the grid, or the value may also be a proportion of the capacity value fed into the grid.

In another example, when the capacity value fed into the power grid is smaller than a first preset value and larger than or equal to a second preset value, the controller determines that the power grid fed into the power grid with the capacity value smaller than the first preset value and larger than or equal to the second preset value is the first power grid. The controller determines the feed-in power grid with the capacity value larger than or equal to the first preset value as a second power grid. Wherein the first preset value is larger than the second preset value. At the moment, the controller adjusts the power supply power of each AC-DC converter according to the capacity value of each feed-in power grid in the first power grid and the second power grid. The calculating step may specifically include:

step 1, determining a first power supply power of a corresponding AC-DC converter according to the capacity value of each feed-in power grid of the first power grid.

In this step, the power value fed into the power grid in the first power grid is smaller than the first preset value and greater than or equal to the second preset value. In this case, the feed grid in the first grid often has a residual capacity available for supplying power to the dc distribution grid after supplying power to the ac loads. However, the remaining capacity of the feed-in power grid is low, and the normal power supply requirement cannot be met.

The controller thus determines the supply power of the corresponding ac-dc converter from the respective capacity value of the first power network fed to the power network. The supply power of the individual ac-dc converters of the first electrical network is denoted as first supply power. The first supply power may be a capacity value fed into the grid, or the first supply power may be a value slightly smaller than the capacity value fed into the grid, or the first supply power may also be a proportion of the capacity value fed into the grid.

And 2, determining a second power supply requirement of the second power grid according to the first power supply power and the first power supply requirement.

In this step, after determining the power supply power of each ac-dc converter of the first power grid, the controller may determine the power supply amount of each ac-dc converter of the first power grid. The supply amount is the sum of the supply powers of the ac-dc converters in the first power grid. The controller determines a second power demand based on a difference between the power demand and the amount of power supplied.

And 3, determining the second power supply power of the corresponding AC-DC converter according to the second power supply requirement and the capacity value of each feed-in power grid of the second power grid.

In this step, the method for determining, by the controller, the second power supply power of the corresponding ac-dc converter according to the second power supply requirement and the capability value of each fed-in grid of the second grid may include at least one of the following:

and the controller calculates to obtain a second average power supply requirement according to the second power supply requirement and the number of the feed-in power grids in the second power grid. And the second average power supply requirement is the quotient of the second power supply requirement divided by the number of the feed-in power grids of the second power grid. The controller determines the second average power supply requirement as the second power supply of the corresponding ac-dc converter.

Or the ratio of the capacity value of one feed-in power grid of the second power grid to the sum of the capacity values of all the feed-in power grids of the second power grid is the capacity value proportion of the feed-in power grid. The controller determines the product of the capacity value and the second power supply requirement as the second power supply of the corresponding AC-DC converter.

Or the controller sequences each feed-in power grid in the second power grid according to the priority of each feed-in power grid in the second power grid. The controller determines the second power supply power of each AC-DC converter in the second power grid one by one according to the priority from high to low. The priority determination method and the method for determining the power supply one by one are consistent with the implementation mode.

And S204, supplying power to the direct current load according to the power supply power.

Step S204 is similar to the step S103 in the embodiment of fig. 2, and this embodiment is not described herein again.

The application provides a multi-feed-in low-voltage direct-current power distribution method. The controller obtains the residual capacity of each feed-in power grid after supplying power to the alternating current load through a detector arranged on the feeder line. The controller determines the remaining capacity as a capacity value of the feed-in grid. The controller determines a first preset value according to the first power supply requirement. When the capacity value of each feed-in power grid of the multi-feed-in low-voltage direct-current power distribution system is larger than or equal to a first preset value, the controller directly determines the power supply power of each alternating-current direct-current converter according to the capacity value and the power supply requirement of each feed-in power grid. When the capacity value of the multi-feed-in low-voltage direct-current power distribution system is smaller than a first preset value, the controller reduces the power supply power of the alternating-current direct-current converter in the first power grid. At the same time, the controller increases the supply power of the ac-dc converter in the second grid. And the controller adjusts the power supply power output by the AC-DC converter to the DC distribution network according to the power supply power, so as to supply power to the DC load. In the application, the accurate configuration of the electric energy of each feed-in power grid in the multi-feed-in low-voltage direct-current power distribution system is realized by adjusting the power supply power of each feed-in power grid, so that the forward mutual assistance of the electric energy among the feed-in power grids is realized, and the utilization rate of electric power resources is improved.

In the above embodiment, when the capacity value of the feeding grid is low, the other feeding grids in the multi-feeding low-voltage dc distribution system can keep the power in the dc distribution grid stable by means of forward mutual compensation. However, when the ac load connected to the feeding grid is heavily loaded, the feeding grid may have a problem that the demand for supplying power to the ac load cannot be satisfied. During normal electricity utilization, when the above conditions occur, normal operation of most loads or normal operation of important loads is generally ensured by disconnecting part of the loads. However, in the present application, the ac-dc converter of the multi-feed low-voltage dc distribution system can be used to convert ac power into dc power, and can also be used to convert dc power into ac power. Therefore, the reverse mutual aid of the multi-feed low-voltage direct current power distribution system is realized. Specific examples of this mode are shown below.

Fig. 4 shows a flowchart of another multi-feed low-voltage dc power distribution method according to an embodiment of the present application. On the basis of the embodiments shown in fig. 1 to fig. 3, as shown in fig. 4, with a controller as an execution main body, the method of the embodiment may specifically include the steps of:

in this embodiment, a second preset value of the parameter is set. Specifically, the second preset value is a capability value close to 0. E.g., -1, 0, 1, etc., whose values are determined according to the carrying capacity of the ac load fed into the grid. When the capacity value fed into the power grid is smaller than the second preset value, the electric energy fed into the power grid is insufficient to support the alternating current load fed into the power grid to work normally. If no other electric energy is supported, part of the alternating current load is limited in current or disconnected.

The controller determines that the feed-in power grid with the capacity value larger than or equal to the first preset value is a second power grid, and determines that the feed-in power grid with the capacity value smaller than the second preset value is a third power grid.

S301, obtaining the capacity value of each feed-in power grid, wherein the capacity value is the residual capacity of the feed-in power grid after power is supplied to the alternating current load of the feed-in power grid.

Step S301 is similar to the step S101 in the embodiment of fig. 2, and this embodiment is not described herein again.

And S302, determining a third power supply power of the corresponding AC-DC converter according to the capacity value of the third power grid, wherein the third power supply power is used for supplying power to an AC load fed into the power grid.

In this embodiment, the feed-in grid in the third grid is a feed-in grid of which the capacity value is smaller than the second preset value. The electrical energy fed into the grid is insufficient to meet the power demand of the ac load. Therefore, the feed network in this third network cannot supply power to the dc distribution network. Moreover, the feeding grid in the third grid has instability because the power of the feeding grid cannot meet the power supply requirement of the alternating current load.

For the situation, the controller determines the power supply amount of each feed-in power grid of the third power grid, which needs to be compensated, according to the capacity value of the third power grid. The supply amount to be compensated is the third supply power of the corresponding ac-dc converter. And, this power supply process is supplying power to the ac loads feeding the grid for the dc distribution grid. Therefore, the power supply direction of the ac-dc converter is dc to ac.

And S303, determining fourth power supply power of the corresponding AC-DC converter according to the third power supply power and the capability value of each feed-in power grid of the second power grid.

In this embodiment, the controller needs to calculate compensation electric quantity needed by the third power grid, and determines the third power supply power of each fed-in power grid in the second power grid according to the compensation electric quantity. The calculation process can be specifically realized by the following steps:

and step 1, determining the total compensation amount according to the third power supply power.

In this step, the third power grid may include at least one feeding power grid. According to step S302, the controller may determine the total compensation amount by accumulating the power supplied by each ac-dc converter in the third power grid.

And 2, determining fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of each feed-in power grid of the second power grid.

In this step, the method for determining, by the controller, the second power supply power of the corresponding ac-dc converter according to the total compensation amount and the capability value of each fed-in grid of the second grid may include at least one of the following:

and the controller calculates to obtain the average compensation quantity according to the total compensation quantity and the number of the feed-in power grids in the second power grid. The average compensation quantity is the quotient of the total compensation quantity divided by the number of the feed-in power grids of the second power grid. The controller determines the average compensation amount as the fourth supply power of the corresponding AC-DC converter.

Or the ratio of the capacity value of one feed-in power grid of the second power grid to the sum of the capacity values of all the feed-in power grids of the second power grid is the capacity value proportion of the feed-in power grid. The controller determines the product of the capacity value proportion and the total compensation amount as the fourth power supply of the corresponding AC-DC converter.

Or the controller sequences each feed-in power grid in the second power grid according to the priority of each feed-in power grid in the second power grid. The controller determines the fourth power supply power of each AC-DC converter in the second power grid one by one according to the priority from high to low. The priority determination method and the method for determining the power supply one by one are consistent with the implementation mode.

And S304, supplying power to the direct current load according to the power supply power.

Step S304 is similar to the step S103 in the embodiment of fig. 2, and details of this embodiment are not repeated here.

The application provides a multi-feed-in low-voltage direct-current power distribution method. The controller obtains the residual capacity of each feed-in power grid after supplying power to the alternating current load through a detector arranged on the feeder line. The controller determines the remaining capacity as a capacity value of the feed-in grid. And when the capacity value of the multi-feed-in low-voltage direct-current power distribution system is smaller than a second preset value, the controller determines the third power supply power of the corresponding alternating-current direct-current converter according to the capacity value of each feed-in power grid of the third power grid. The third supply power is used to supply an ac load fed to the power grid. The controller counts the total compensation required by the third power grid. And the controller determines the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of each fed-in power grid in the second power grid. And the controller controls the AC-DC converter to supply power to the AC load according to the fourth power supply. In the application, the power supply to the alternating current load realizes reverse mutual assistance, so that the stability of the feed-in power grid is improved, and the utilization rate of power resources is improved.

Fig. 5 is a flowchart illustrating a method for multi-feed low-voltage dc power distribution according to an embodiment of the present application. On the basis of the embodiments shown in fig. 1 to 4, as shown in fig. 5, with a controller as an execution main body, the method of this embodiment may specifically include the steps of:

s401, charging information of the charging vehicle in the charging station is obtained. The charging information of the charging vehicle is sent to the controller by the charging station.

In this embodiment, the dc load connected to the dc distribution network may include a charging station. When the electric vehicle is connected to the charging station, the charging station sends a power distribution request to the controller. The power distribution request includes a power supply demand, charging information of the charging vehicle, and the like.

S402, determining the use conditions of the charging station and the charging vehicle according to the charging information.

In this embodiment, the charging information may include a charging time period, a charging amount, a charging voltage, a charging current, and the like. And after receiving the charging information, the controller judges whether the charging vehicle is normally charged according to the charging information.

For example, the controller may determine that an abnormality occurs in the charging vehicle when the charging period exceeds a preset period. Alternatively, the controller may determine that an abnormality occurs in the charging vehicle when the charging voltage exceeds a preset voltage.

And S403, when the charging station or the charging vehicle is abnormal, sending alarm information, wherein the alarm information is used for reminding an administrator of the abnormality of the charging station or the charging vehicle.

In this embodiment, when the controller finds that the charging information is abnormal, the controller determines that the charging vehicle is abnormal. The controller determines alarm information according to the abnormal information. The controller transmits the alarm information. The controller can send the alarm information to a prestored mobile phone number, and the sending mode can include short message, multimedia message and the like. Alternatively, the controller may also send the alert message to a pre-stored mailbox. Alternatively, the controller may send the alarm information to an administrator side of the platform through the platform. Or the controller can also control equipment such as a buzzer to be started to remind field workers to carry out treatment.

The application provides a multi-feed-in low-voltage direct-current power distribution method. The controller acquires usage information of the dc load, such as charging information of a charging vehicle in the charging station, and the like. The controller determines the use conditions of the charging station and the charging vehicle according to the charging information. When the charging station or the charging vehicle is abnormal, the controller sends alarm information. In this application, through the detection to the service behavior of charging station and charging vehicle, realize unusual warning, improve direct current distribution network's power consumption safety.

On the basis of the above embodiment, the controller is further configured to control the switch to be turned on or off. In particular, the detector is also installed in a direct current distribution network. The detector sends the voltage or current of the direct current load or the bus to the controller in real time. When the controller detects that the data of the detector is abnormal, the controller can control the corresponding switch to be switched off, so that the normal operation of the region without fault is ensured. Among them, a plurality of switches corresponding to the data abnormality detectors may be provided.

In the multi-feed-in low-voltage direct-current power distribution method provided by the application, the controller judges whether the direct-current load or the bus normally operates or not through acquiring detection data of the detector. When the direct current load or the bus is abnormal, the controller controls the corresponding switch to be switched off, so that normal operation of an area without faults is guaranteed, the power utilization safety of the direct current power distribution network is improved, and the stability of the direct current power distribution network is improved.

On the basis of the above embodiment, the direct current load may also be an energy storage power station. The working steps of the energy storage power station can comprise:

step 1, obtaining the statistical value of each ability value fed into the power grid in each time period.

In this step, the control system further comprises a statistical table for counting the ability values of the fed-in power grids in each time period. Wherein, the time period can be divided by hours, one hour by one time period, or several hours by one time period, etc. The power value fed into the power grid during a time period may be an average value calculated after sampling the power value fed into the power grid during the time period. Wherein, the sampling frequency can be once in 10 minutes, once in one minute, and the like.

When the statistical time in the statistical table is more than one day, the controller calculates and determines the average value of the uniform time interval as the statistical capability value of the time interval.

And 2, determining an energy storage time period according to the statistical capacity value and the preset capacity value.

In this step, the controller obtains a time period in which the statistical power value is greater than the preset value from the statistical table. The controller determines the period as an energy storage period. Wherein, the preset capacity value is a numerical value set by an administrator according to experience. And when the statistical capacity value is larger than the preset capacity value, considering that the electric energy fed into the power grid in the period is in an idle state.

And 3, adjusting the power supply power of the AC-DC converter according to the energy storage time period, the energy storage of the energy storage power station and the energy values of all the fed-in power grids.

In the step, when the energy storage time period is up, the controller starts to control the energy storage power station to store energy. The controller obtains the stored energy of the energy storage power station. The stored energy is the amount of electric energy which can be stored in the energy storage power station, specifically the difference of the total stored energy minus the current stored energy. And the controller acquires the capacity value of each feed-in power grid and the power supply power of the corresponding AC-DC converter.

And the controller determines the total power supply requirement at the current moment according to the stored energy and the power supply requirement at the current moment. And the controller determines the current power supply power of each AC-DC converter according to the total power supply requirement at the current moment and the capacity value of each fed-in power grid. The controller adjusts the power supply power of each AC-DC converter to the current power supply power.

And 4, storing energy in the energy storage power station according to the adjusted power supply power.

In the multi-feed-in low-voltage direct-current power distribution method, the controller stores the electric energy fed into the idle time periods of the power grid into the energy storage power station, time-sharing multiplexing of the electric energy is achieved, and the electric energy fed into the idle time periods of the power grid can be multiplexed in busy time periods. Through this mode, many feed-in low pressure direct current distribution system can improve the electric energy availability factor, improves the stability of direct current distribution network and feed-in electric wire netting.

Fig. 6 is a schematic structural diagram of a multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present invention, and as shown in fig. 6, the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment is used to implement operations corresponding to a controller in any of the above method embodiments, where the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment includes:

the first obtaining module 11 is configured to obtain a capability value of each feed-in power grid, where the capability value is a remaining capacity of the feed-in power grid after the feed-in power grid supplies power to an ac load of the feed-in power grid.

A first determining module 12, configured to determine the supply power of each ac-dc converter according to the capability value of each fed grid and the first power supply requirement.

And the power supply module 13 is configured to supply power to the dc load according to the power supply power.

The multi-feed-in low-voltage dc power distribution apparatus 10 provided in the embodiment of the present application can implement the above method embodiment, and specific implementation principles and technical effects thereof can be referred to the above method embodiment, which is not described herein again.

Fig. 7 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present invention, and based on the embodiment shown in fig. 6, as shown in fig. 7, the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment is used to implement operations corresponding to a controller in any of the method embodiments described above, and the first determining module 12 of the present embodiment includes:

the first determining submodule 121 is configured to determine a first preset value according to a power supply requirement;

and the second determining submodule 122 is used for determining the power supply power of each AC-DC converter according to the first preset value, the capacity value of each feeding power grid and the power supply requirement.

In one example, when the capability value of each feeding grid is greater than or equal to the first preset value, the second determining sub-module 122 specifically includes at least one of the following: determining the average value of the power supply power of each AC-DC converter according to the power supply requirement, wherein the average value is the quotient of the power supply requirement divided by the number of the fed-in power grids; determining the power supply power of each AC-DC converter according to the power supply requirement and the capacity value of each feed-in power grid; and determining the power supply power of each AC-DC converter according to the power supply requirement, the capacity value of each feed-in power grid and the priority of each feed-in power grid.

In another example, when the capability value of the feeding power grid is smaller than a first preset value and larger than or equal to a second preset value, determining that the feeding power grid with the capability value smaller than the first preset value and larger than or equal to the second preset value is a first power grid, and determining that the feeding power grid with the capability value larger than or equal to the first preset value is a second power grid, wherein the first preset value is larger than the second preset value;

the second determining submodule 122 specifically includes: determining a first power supply power of a corresponding AC-DC converter according to the capacity value of the first power grid; determining the power supply requirement of a second power grid according to the first power supply power and the power supply requirement; and determining the second power supply power of the corresponding AC-DC converter according to the power supply requirement of the second power grid ground and the capacity value of the second power grid.

The method for determining the second power supply power of the corresponding AC-DC converter according to the power supply requirement of the second power grid ground and the capacity value of the second power grid comprises at least one of the following steps: determining the average value of the power supply demand of the second power grid as the power supply power of the corresponding AC-DC converter, wherein the average value is the quotient of the power supply demand divided by the number of the feed-in power grids of the second power grid; determining the power supply power of the corresponding AC-DC converter according to the power supply requirement of the second power grid and the capacity value of the second power grid; and determining the power supply power of the corresponding AC-DC converter according to the power supply requirement of the second power grid, the capacity value of the second power grid and the priority of the second power grid.

Fig. 8 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present application, and based on the embodiments shown in fig. 6 and fig. 7, as shown in fig. 8, the multi-feed low-voltage dc power distribution apparatus 10 of this embodiment is used to implement operations corresponding to a controller in any of the method embodiments described above, and the first determining module 12 of this embodiment further includes:

when the capacity value of the feed-in power grid is smaller than a second preset value, determining the feed-in power grid with the capacity value smaller than the second preset value as a third power grid, and determining the feed-in power grid with the capacity value larger than or equal to the first preset value as a second power grid, wherein the first preset value is larger than the second preset value;

a third determining submodule 123, configured to determine, according to the capability value of the third power grid, third power supply power of an ac-dc converter of the third power grid, where the third power supply power is used to supply power to an ac load fed into the power grid;

and the fourth determining submodule 124 is configured to determine a fourth power supply of the corresponding ac-dc converter according to the third power supply and the capability value of the second power grid.

In one example, the fourth determining submodule 124 is specifically configured to determine the total compensation amount according to the third power supply; and determining the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of the second power grid.

And determining the fourth power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of the second power grid, wherein the fourth power supply power comprises at least one of the following: determining the average value of the total compensation quantity as the power supply power of the corresponding AC-DC converter, wherein the average value is the quotient of the power supply demand divided by the number of the feed-in power grids of the second power grid; determining the power supply power of the corresponding AC-DC converter according to the total compensation amount and the capacity value of the second power grid; and determining the power supply power of the corresponding AC-DC converter according to the total compensation amount, the capacity value of the second power grid and the priority of the second power grid.

Fig. 9 shows a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present application, and based on the embodiments shown in fig. 6 to fig. 8, as shown in fig. 9, the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment is used to implement the operation corresponding to the controller in any of the method embodiments described above, and the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment further includes:

the statistical module 14 is used for acquiring statistical capacity values of the capacity values of all the feed-in power grids in all time periods;

the second determining module 15 is configured to determine an energy storage time period according to the statistical capability value and the preset capability value;

the adjusting module 16 is used for adjusting the power supply power of the ac-dc converter according to the energy storage time period, the energy storage of the energy storage power station and the energy values of the fed-in power grids;

and the power supply module 13 is further configured to store energy in the energy storage power station according to the adjusted power supply power.

Fig. 10 is a schematic structural diagram of another multi-feed low-voltage dc power distribution apparatus according to an embodiment of the present application, and based on the embodiments shown in fig. 6 to 9, as shown in fig. 10, the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment is used to implement the operation corresponding to the controller in any of the method embodiments described above, and the multi-feed low-voltage dc power distribution apparatus 10 of the present embodiment further includes:

and a second obtaining module 17 for obtaining the charging information of the charging vehicle in the charging station. The charging information of the charging vehicle is sent to the controller by the charging station.

And a third determining module 18, configured to determine, according to the charging information, usage of the charging station and the charging vehicle.

And the alarm unit 19 is used for sending alarm information when the charging station or the charging vehicle is abnormal, wherein the alarm information is used for reminding an administrator of the abnormality of the charging station or the charging vehicle.

Fig. 11 shows a schematic structural diagram of a multi-feed low-voltage dc distribution system according to an embodiment of the present invention, and as shown in fig. 11, the multi-feed low-voltage dc distribution system 20 of the present embodiment includes a dc distribution network 21, a controller 22, and a plurality of feed grids 23.

The feed network 23 is connected to the dc distribution network 21 via an ac-dc converter 24.

The controller 22 is connected to the dc distribution network 21, and the controller 22 is configured to control an output parameter of the ac-dc converter 24 according to each input parameter fed into the dc distribution network 21, so as to stabilize an operating parameter of the dc distribution network 21.

The dc distribution network 21 is provided with at least one output port for connection to an external dc load 25.

In one example, the output port is connected to the ac-dc converter and the dc load via a bus or a cable.

In one example, the multi-feed low voltage dc distribution system 20 further includes a switch 26.

The switch 26 is used to control the connection or disconnection of the joining device, wherein the joining device includes at least one of the feeding grid 23, the dc load 25, the bus bar, and the cable.

In one example, the dc load 25 includes an energy storage power station 251.

The energy storage power station 251 is used for storing energy when the power resources of the dc distribution network 21 are sufficient, and releasing energy when the power resources of the dc distribution network 21 are in short supply.

In another example, the dc load 25 includes a charging station 252.

The charging station 252 is configured to send charging information of the charging vehicle to the controller 22, so that the controller 22 determines the charging condition of the charging vehicle according to the charging information.

In one example, the feed grid 23 includes a transformer 231, a feeder 232, and an ac load 233.

In one example, the topology of the dc distribution network is any one of a ring network structure, a star structure, and a radiation structure.

In one example, the multi-feed low voltage dc distribution system 20 further includes a plurality of detectors 27.

The detector 27 is installed in the feeding network 23 and is used for obtaining the power consumption of the ac load 233 in the feeding network 23. The detector 27 is installed on the dc distribution network 21 and is used for measuring the amount of power output from the dc distribution network 21 to the dc loads 25 and the amount of power flowing through the bus or cable of the dc distribution network 21.

The multi-feed-in low-voltage dc power distribution system 20 provided in the embodiment of the present application may implement the method embodiment, and specific implementation principles and technical effects thereof may refer to the method embodiment, which is not described herein again.

Fig. 12 is a schematic structural diagram of a microprocessor-based controller according to an embodiment of the present invention, and as shown in fig. 12, the controller 30 of the present embodiment includes: a communication interface 31, a processor 32 and a human machine interface 33.

The communication interface 31 is configured to obtain input parameters of the dc distribution network and the fed-in power grid, where the input parameters include current, voltage, power supply time, power supply amount, and operation state.

The communication interface 31 is further configured to output the control instruction or the output parameter after the processor obtains the control instruction or the output parameter through calculation according to the input parameter. For example, when the output parameter is output to the ac-dc converter, the output parameter may be used to control the ac-dc converter to perform ac-dc conversion. The output parameter may specifically include a power supply power, a power supply direction, and the like. Alternatively, when the control instruction is output, the control instruction may be output to a switch for controlling the switch to be disconnected or connected.

And a processor 32 for implementing the multi-feed low-voltage dc power distribution method according to the embodiment shown in fig. 2 to 5. The Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the present invention may be embodied directly in a hardware processor, or in a combination of the hardware and software modules within the processor.

And the man-machine interface 33 is used for realizing the interaction between the multi-feed low-voltage direct-current power distribution system and an administrator. The interaction comprises the steps of obtaining the setting of an administrator and outputting abnormal alarm information to the administrator.

The microprocessor may also include a memory 34 for storing parameter information for the multi-feed low voltage dc power distribution system. Wherein a memory 34 may be coupled to the processor 33, such that the processor can read information from the memory 34 and write information to the memory 34. Of course, the memory 34 may also be an integral part of the processor. The processor 33 and the memory 34 may be located in an Application Specific Integrated Circuits (ASIC). Additionally, the ASIC may reside in user equipment.

The Memory 34 may be implemented by any type of volatile or non-volatile Memory device or combination thereof, such as Static Random-Access Memory (SRAM), Electrically-Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic Memory, flash Memory, magnetic disk or optical disk. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The present application also provides a program product comprising execution instructions, the execution instructions being stored in a memory. The at least one processor of the device may read the execution instructions from the memory, and the execution of the execution instructions by the at least one processor causes the device to implement the methods provided by the various embodiments described above.

Embodiments of the present application further provide a chip, which includes a memory and a processor, where the memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that a device in which the chip is installed executes the method in the above various possible embodiments.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, the division of the modules is only one logical division, and the actual implementation may have another division, for example, a plurality of modules may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or modules, and may be in an electrical, mechanical or other form.

Modules described as separate parts may or may not be physically separate, and parts displayed as modules 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 modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

In addition, functional modules in the embodiments of the present application may be integrated into one processing unit, or each module may exist alone physically, or two or more modules are integrated into one unit. The unit formed by the modules can be realized in a hardware form, and can also be realized in a form of hardware and a software functional unit.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: it is also possible to modify the solutions described in the previous embodiments or to substitute some or all of them with equivalents. And the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-feed-in low-voltage direct-current power distribution system is characterized by comprising a direct-current power distribution network, a controller and a plurality of feed-in power grids;

the controller is connected with the feed-in power grid and the direct-current power distribution network, is used for controlling output parameters of the alternating-current-direct-current converter according to input parameters of the feed-in power grids so as to stabilize working parameters of the direct-current power distribution network, and is connected to the feed-in power grid and the direct-current power distribution network through cables or optical fibers;

2. The multi-feed low voltage dc power distribution system of claim 1, further comprising: a switch;

3. The multi-feed low voltage dc power distribution system of claim 1, wherein the dc load comprises an energy storage power station;

4. The multi-infeed low-voltage dc power distribution system as recited in claim 1, wherein said dc loads comprise charging stations;

5. The multi-feed low voltage dc distribution system according to claim 1, wherein the feed grid comprises a transformer, a feeder and an ac load.

6. The multi-feed low-voltage DC power distribution system according to any one of claims 1 to 5, wherein the topology of the DC power distribution network is any one of a ring network structure, a star structure and a radiating structure.

7. A multi-feed low-voltage dc power distribution method applied to the multi-feed low-voltage dc power distribution system according to any one of claims 1 to 6, wherein the method comprises:

8. The method according to claim 7, wherein determining the supply power of each ac-dc converter according to the capacity value and the first supply demand of each feeding network comprises:

9. The method according to claim 8, wherein when the capability value of each feeding grid is greater than or equal to a first preset value, the determining the power supply power of each ac-dc converter according to the first preset value, the capability value of each feeding grid and the first power supply requirement comprises at least one of:

10. The method of claim 8,

when the capacity value of the fed-in power grid is smaller than the first preset value and larger than or equal to a second preset value, determining that the capacity value is smaller than the first preset value, the fed-in power grid larger than or equal to the second preset value is a first power grid, and determining that the fed-in power grid of which the capacity value is larger than or equal to the first preset value is a second power grid, wherein the first preset value is larger than the second preset value;

11. The method of claim 7, comprising:

12. The method according to claim 11, wherein determining the fourth supply power of the ac-dc converter according to the third supply power and the capability values of the respective feeding grids of the second grid comprises:

13. The method according to any of claims 7-12, wherein the direct current load comprises an energy storage plant, the method comprising:

14. The method of any one of claims 7-12, wherein the dc load comprises a charging station, the method comprising:

15. A multi-feed low voltage dc distribution device, the device comprising: a controller, an AC-DC converter and a detector;

the first acquisition unit is used for acquiring the capacity value of each feed-in power grid, wherein the capacity value is the residual power resource amount after the feed-in power grid supplies power to an alternating current load in the feed-in power grid;

the first determining unit is used for determining the power supply power of each AC-DC converter according to the capacity value and the first power supply requirement of each feed-in power grid;

and the power supply unit is used for supplying power to the direct current load according to the power supply power.

16. A controller, comprising: a communication interface, a processor and a human-machine interface;

the communication interface is used for acquiring input parameters of each device of the multi-feed-in low-voltage direct-current power distribution system, wherein the input parameters comprise current, voltage or running state, and the communication interface is also used for outputting control instructions and output parameters to each device of the multi-feed-in low-voltage direct-current power distribution system;

the processor is used for realizing the multi-feed low-voltage direct-current power distribution method according to any one of claims 7 to 14;